Ratna Sagar Jewels - All Types of Wholesale Gemstone Beads

Scorpio is the most emotional of all zodiac signs, and several birthstones have been associated with this zodiac. The different birthstone act as lucky stones or charms and they can absorb the negative energy, thereby promoting positive energy. People, who are born between October 24 to November 21st come under this sun sign. Pluto is the ruling planet, and its position in the birth planet can create a great impact on the character and relationship of a person. The main birthstone of Scorpio is Topaz, but there are many more other stones associated with this sun sign. Let us take a look at 5 Gemstones for people born under Scorpio Zodiac Sign:

1.  Topaz:

Scorpio is considered to be the most powerful of all zodiac signs, and it can create a dual impact. Therefore, a scorpion individual requires Topaz for creating an inspiring and stimulating influence on both the mind, and the soul. Topaz gemstone beads conduct the energies of the ruling planet, Pluto. It plays a great role in enhancing the area of relationship with loyalty, constancy and faithfulness. It is important to note that the strong influence of Topaz can create a balancing effect on the nervous system and the chakras. Apart from that, it can even heal health issues like gout, asthma problems, mental issues, sleeping disorders, etc.

2.  Aquamarine:

It is the traditional birthstone of Scorpio according to the old Arabic, polish, Hebrew and Roman calendar. The Aquamarine Gemstone variety of this stone can bestow some of the best foresight to the wearer. In addition to that, it is even to known to relieve stress and anxiety, thereby stimulating youthful joy and happiness.
3.  Opal:

Opal is one of the amazing gemstones that work for Scorpio people. It is ruled by Pluto. The stone is mystic, healer and artist. Moreover, this stone is also known for offering its support during times of transition and intense change.  

4.  Beryl:

This stone belongs to a group of minerals, which even include aquamarine. In the old Italian and Russian calendar, this was the birthstone of October. The precious stone can be found in wide varieties of colors except green. The green one is known as emerald. The stone can bring joy and cheerfulness in a solemn and serious Scorpion. In addition to that, it can even enrich the power of love and marriage. Yellow colored beryl is the most suitable color for people belonging to Scorpio zodiac, and it deepens the level of sincerity in a person.

5.  Tourmaline:

Also known as Rubellite is often associated with Scorpio. It influences a person with positive energy. Moreover, it might even strengthen blood, thereby providing complete balance to the structures of blood vessels and veins. This in turn promotes blood circulation. The Tourmaline Beads can even heal the nervous system, especially in people born to a Scorpio sun sign.

Apart from these five there are several other gemstones that contemporary astrologers describe as the birthstone of Scorpio. You need to find out what suits you the best, and which of them proves to be lucky for you. On the basis of that, you can make your decision.     

A rousing gemstone in its purple brilliance, amethyst is one of the key items used in jewellery. Essentially quartz, amethyst gemstones is derived from Greek, which translates to “protected from intoxication”. Its natural colour ranges from light pink to deep overtones of purple, often resembling pigeon’s blood.

In the market, finding a brilliant purple amethyst gemstone from natural deposits is almost impossible. Amethyst gemstones are produced abundantly from the mines of Brazil, to be precise, at Minas Gerais. A place in South Brazil that is revered for its rich paleontological importance, the mines produce largest deposits of the Sobriety Stone.

In order to exaggerate the light shaded amethyst stones produced from mines elsewhere other than Brazil, the gems are treated synthetically. The colour and the properties attained after undergoing the treatments remain irreversible.

Why is Amethyst Purple?

Amethyst is quartz with iron and aluminium impurities impregnated in the structure. Closest siblings to amethyst are Golden citrine and Ametrine.
Here are different amethyst treatments and the effect they have on their commercial value and pricing.

Heating:

The finest quality of amethyst stones exhibits a strongly reddish purple to light pink with zero zoning on them. Gem dealers prefer to display only amethyst stones with saturated reddish purple with a bright radiance. Natural dark amethyst may look blackish when observed in dim lights.

This is where heat treatment is brought into the picture. Very dark amethyst gemstones are gased in high temperatures to lighten the shade. When done in controlled temperatures, gem manufacturers actually manage to produce light but more saturated shades.

Heating is done at 400 degrees to produce astonishingly stable shades of royal purple. It causes tiny inclusions due to expansion of fractures already existing in the crystal structure. The process imparts a permanent colour that will last forever. All dramatic coloured amethysts have undergone heat treatment at some point of their life.

Irradiation:

Sometimes when amethyst gems are not available in the market as per demand, the lapidary takes irradiation as a primary course to produce synthetic amethysts. Commonly, synthetic gemstones are made to resemble amethyst by bombarding Yellow Citrine with Gamma rays. The iron oxide particles in the crystal structure of yellow citrine re-oxidize to give it a natural looking purple shade.

The advantages of using irradiation process to produce marketable amethyst gemstone beads are:

• 100% reversible process, if not subjected to heat treatment
• Cheaper process if done for bulk orders
• A large variety of stones can be used to produce amethyst under lab conditions

Amethyst Treatment:

Amethyst is seldom subjected to heat treatment. The transformation of amethyst gemstones yield Vermarine or Prasiolite, as it is known more commonly in the market. Natural looking Brazilian amethysts turn to the green-coloured vermarine, at a temperature ranging between 800 to 1350 degrees.

Treated amethyst is cut in rounds and ovals, and hardly in cabochon. Calibrated sizes of amethyst can be shaped in exotic patterns resembling hearts, trillions and shields. Ornamental carvings made of amethyst retain their shade and physical brilliance much longer.

Considered as the tears of the angels, gemstones are one of the most fascinating creations in the Universe. The oldest known gemstone treasury belonged to Egyptian queen Cleopatra, and today one of the world’s largest gemstone collections belongs to Queen of England, something worth over $80 million. Diamonds, emerald and rubies are quintessentially the top gems known for their rare beauty. However, there are some paltry crystals that rank higher than the commonly known gems.

Painite

The name Painite commemorates the person who discovered the stone- Arthur C.D. Pain.Already listed in the Guinness World Recordsas the rarest gem mineral not just on Earth but also in the Universe, Painite is the costliest known naturally occurring material. A carat costs anywhere between $18000 and $50000, meaning you can buy at least a dozen rubies at the cost of one 1-carat Painite. 

How it looks like

Painite is a dark red gemstone showcasing varied hues when viewed from different angles. It also shows a distinct green colour under UV. Mogok in Myanmar is the only known site of extraction for Painite. The major constituents of Painites are calcium, zirconium, boron, aluminium, chromium and vanadium. 

Fact: 

Painite exhibited at the Tucson Gem & Mineral Show, Arizona was tagged at $60,000 per carat.

Bixbite

More popularly called as the Red Beryl, Bixbite was first discovered by renowned gem collector Maynard Bixby. Mined from the Wah Wah Mountains in Utah, the price of 1-carat Bixbite is $12000. The most popular bixbite is the Ruby Violet Claims which is currently priced at $10 million. 

Bixbite is found only in Utah, but some gem researchers also discovered pezzottaite in Madagascar and Afghanistan which resemble these costly gems.

Fact:

Bixbite is a red beryl. However, gem buyers often confuse the gem with bixbyite which is a black coloured manganese iron oxide mineral. The names however have been attributed to the same person who discovered the gemstones. 

Serendibite

Found sparingly in Sri Lanka, Serendibite is a greenish blue coloured gemstone. The name is derived from Arabic word for Sri Lanka- “Serendib”.  It has an opaque appearance and exhibits pleochroism in golden brown, green and blue under diffused low wavelength light.

1-carat Serendibite can cost up to $15000 owing to the rarity. It features a very rare composition of calcium, magnesium, aluminium, iron, boron and silicon. It is 100% inert to UV fluorescent light making it all the more difficult to identify. 

Fact: 

Serendibite is used exclusively for black gemstone jewellery.

Poudretteite

Officially named after the Poudrette family, this gemstone belongs to the crystal group of cyclo-silicates. First discovered in Quebec, Canada Poudretteite is a relatively soft gemstone (Mohs hardness- 5.0) bearing pink and violet shades with prismatic hexagonal cuts. Mogok valley is the largest producer of Poudrettite.

We can only speculate about its price.As per gem auction tags, it is usually priced from $2000 to $10 million per carat.

Fact: 

A 9-carat Poudretteite remains the heaviest gemstone ever mined.

In a world driven by the love for diamond and ruby beads, garnets, the pearls have a place of reverence in the gemstone market. Revered for their clarity and pristine beauty, since time immemorial, pearls have always been an item of great respect. From finding a place in God’s necklace to shining majestically atop the crowns of most powerful rulers, there is a story behind every pearl. After all, pearls are one of the few known organic gemstones found exclusively on the planet.

Not all naturally produced pearls have the signature lustre and translucency. Most pearls require an additional treatment to derive the clear appearance. 

Here is what you should know about pearl treatments in a highly competitive industry.

Accepted commercial pearl treatments 

Polishing is a world-renowned process done to improve the lustre of the pearls. It has been established as an accepted process since many centuries, much before the technology to dye and heat up the pearls were discovered.

The common treatment used in pearl manufacturing and marketing industry are:

Irradiation 

Bleaching and dyeing

Heating

Waxing 

Filling and working

Drilling

Cutting

Any treatment is engaged in pearl manufacturing only after ensuring its credibility in alleviating the aesthetic and economical value of the item. All pearls are anyhow polished and cleaned off the organic debris before setting up for sale in the market.

For a lustrous shine, a pearl is subjected to following treatments.

Dyeing

Pearls are subjected to a solution of silver nitrate and oils. They give the pearl gemstones a more uniform shade. The use of silver nitrate works in the same way as in the development of a photographic film in dark room. The pearl gets a rich metallic sheen with a blackish shade. Over a period of time, the effect of dyeing fades away.

Irradiation

It is done using powerful gamma radiations on Akoya pearls. Since it involves use of radiation, only certified pearl treatment units are allowed to carry out the process legitimately. 

The irradiation produces a more consistent appearance, with iridescence conspicuously visible on the surface. Unlike dyeing, irradiation of pearl gives a long lasting effect.

Maeshori

Though a Japanese term, this treatment has found its way into freshwater pearl and Tahitian pearl manufacturing. The process involves systematic heating and subsequent cooling of the pearl to tighten up the nacre. It is more of a makeover or a facelift for the pearls, deriving a rather long-lasting lustre without the involvement of any chemical agent.

Treatment traces in the market

Some pearls can lose their sheen by the time they reach the market. Some of them may even lose it after buying! As a pearl lover, you must verify the authenticity of the pearls beforehand by checking out the nature of treatment done during processing. 

From concentration to consistency, an artificially enhanced pearl is hard to detect unless tagged correctly by the manufacturer. The only way to find out the true story of pearl treatment after processing is to do a destructive test! And it is a very expensive test to perform.

Pearl is one of the oldest known gemstone. Along with amber, corals, jets and ivory, pearl is the only known organic gemstone that retains its place in the list of precious items in the world. Ivory and coral have witnessed a reasonable decrease in market share, considering the environmental regulations imposed on their extractions. However, as pearls make a wave of adulation across world, there are some critical points you should know while buying them, especially related to their culture, surface finishing, and commercial selling.

Pearl farming

Also called as pearl culture, pearl farming is a technology-driven science today. Cultured pearls are grown in controlled biological conditions using different varieties of molluscs. Depending on the family of bivalve molluscs, there are different varieties of pearls.

The pearl oysters used on pearl farming are:

Freshwater mussels 

Marine pearl oysters

It is worth noting the fact that all shelled molluscs are known to produce “pearl” material in some form or the other. It is only the nacre secretion that gives the pearl its signature lustre and value.

Pearl finishing

Due to the reduced term of pearl culture, the quality has significantly dropped. Thus, it calls for finishing process that give the pearls their iconic lustre, reflection .refraction and diffraction properties. The degree of translucency heavily depends on the precision of finishing process. 

Here are some of the accepted finishing treatments done on nacre pearls.

Polishing 

It is a common treatment done on pearls coming from South China Sea. The pearl is tumbled in concentrated brine solution, which removes the layers of mucus and tissues over the surface. Polishing is also done by bleaching the surface to make them appear brighter. 

Polished pearls are available in cream, light pink and yellow-brown shades. Unlike natural pearls, polished pearls show better results when polished with abrasive solutions.

Maeshori

Ever heard of heat treatment on pearls? Yes, Maeshori is a unique Oriental pearl treatment that involves dipping of the Akoya pearls in a methanol solution. It effectively removes all impurities on the surface and also gives it a naturally brighter appearance, resembling the natural ones. 

As far as duration of soaking is concerned, a pearl can be dipped in the alcohol solution for as long as 45 days! The treatment not only removes the impurity, but also heals the pearl of its flaws, cracks and roughness. 

Bleaching 

A rather corrosive pearl treatment, this is done only to give the surface a more uniform appearance. It is applicable to pearls with thin nacre shell. Pearls with thick nacre are kept away from this processing. 

Buffing

Often done to remove visible scratches on the surface, buffing with beeswax and chemical agents is a wasteful method that penetrates deep into the nacre. It is recommended only for minor scratches. 

Lacquer coating 

Pearls with light lustre are coated with lacquer to improve brilliance. It is a temporary treatment that often wears out. Commercial pearls are coated with silicone polymer coatings, but it not a widely accepted treatment. 

In a nutshell, the cost of pearls drop significantly if there is any visible sign of surface finishing. That’s why natural pearls command a higher price in the market.

As kids, we all loved collecting items that meant a lot to us then.  In gemstone market, there are a handful of collectors who are in a serious business of collecting rarest of the rare gemstones and displaying their prized possessions at a handsome price. If you are smitten by the shiny hard rocks, here are some truly delightful gemstones that you can consider collecting and build a gallery of your own.

But before that a few guidelines and tips.

1 Unique and incredibly rare

Not all gemstones are not that fascinating as say a peridot or a garnet or even an emerald. You have to be really choosy in collecting only those gemstones that have a reputation of being rare or unique in their own ways. 

2 Colour and clarity

Shiny and brilliant gems have a higher adulation than the opaque ones. If you are truly in the game of collecting unique gemstones, try segmenting your gallery in terms of optical properties, colour and even cuts and shapes. 

3 Price tag

Oh yes, this is the most uncomplicated filter for any collector. Higher the price higher will be the fan-following! There are high-priced gemstones that you may not have even heard of... Explore them beyond the world of diamonds, rubies and ambers. 

4 Care and maintenance 

Most gemstones require an elaborate care and maintenance routine, and that’s where full-time collectors score big. They rely a lot on technology and latest in gemstone cleansing methods. 

5 The world of faux pas

The life of a gemstone collector revolves around trust and reputation. Even if you manage to collect and display a single gemstone- real and verified source, you are right up there in the league of top professionals. Don’t rely on cheap sources. You are what your gemstone sources make you.

New world of gemstones 

For the love of intense colour and high-quality brilliance, you can start exploring a whole new dimension in gemstone collection. Here are some of the least heard gemstones that most collectors usually have hard time finding in the local market.

Hauyne

This beautiful energetic blue-coloured gemstone belongs to the family of sodalite. First discovered in 1807 in Italy, this gemstone has the highest refractive index for any naturally occurring item- 1.50! 

Known sources of Hauyne are Mount Vesuvius, Lake Laach (Germany), Alban Hills (Rome) and Cripple Creek (Colorado, USA).

Kyanite

Another blue gemstone belonging to the family of alumina-silicates, Kyanite is exclusively used in the electronic industry. Priced at $50-100 per carat, there are other varieties of Kyanite occurring in shades of pink, red, orange and blue-green.

Cerrusite

Heard of the Light of the Desert! It is the largest known cerrusite ever discovered on the planet. Cerrusite means ‘White lead’, and this gemstone is actually an ore of lead. It is a prized collection owing to higher dispersion rating of 0.055 compared to diamond. 

For an instant start

If you wish to start with a safe foundation in gem collection, try out Burmese rubies, Sri Lankan emerald gemstone, Kashmir sapphire gemstone and Tanzanian garnets. You can easily build a respectable collection of real and marketable gemstones in less than a year.

There was a time when rubies ruled the market. Despite their fault lines and flaws, the rubies old like hot buns. But today, if you are looking for clear brilliantly cut rubies, you would be disappointed, especially if you are planning to buy from a staple street-side market. Ever since the hybrid rubies have come into the market, the demands for artificial glass-filled gemstones have drastically fallen.

Why is that so? Well, the major reason behind the success of the hybrid rubies is its proximity in character to the naturally mined rubies and sapphire gemstone. Minus the flaws and add the durability- that is what hybrid ruby gemstones are all about.

If you are searching for rubies in the gemstone market, here is how you can make a distinct and informed choice on hybrid rubies and the real ones.

Do all rubies require hybrid processing?

No, all rubies don’t require hybrid processing. Despite the fact that only 1 in 100 naturally mined gemstones is ranked as the perfect stone, it is still considered as a healthy ratio. In order to save on the cost of commercial mining, the remaining 99 percent rubies are treated artificially with heat treatments, glass lead filling and other low-cost procedures. 

Is hybrid ruby a misrepresentation in the gemstone industry?

There is still a lot of confusion surrounding the status of hybrid rubies. Many organizations consider the hybrid/ composite rubies as the corrected versions of natural gemstones. For them, the only difference in the two varieties lie in the way fractures and flaws appear under the microscope! 

If you take into account the degree of stability and the cleaning process, the hybrid gemstones can’t match up to what natural gemstones deliver. Of course, the fragile gems like lapis lazuli, onyx and opal are distinct exceptions to these misrepresentations.

As per the latest rulings by international bodies regulating the gemstone quality, hybrid rubies are not same as the natural ones. They are not even an extension of the real ones. 

Why are they in so much demand?

First, the cost of hybrid rubies is nowhere close to what real ones are demanding.  But even if you consider the cost of manufacturing a one carat hybrid ruby, it is an economical affair, with numerous profit channels. Big industries like jewellery makers, fashion apparels, art decors dealers and trophy makers rely heavily on the supply of such beautiful and sparkling hybrid gems, creating a steady flow of demand for these rocks.

Even at 40% lead-glass composition, these hybrid gemstones easily rake in a price tag of USD 50-75 per carat. 

The good and the bad of hybrid rubies 

Hybrid rubies look delightful and can be almost passed off as a real ruby set. Even under the microscope, they look just as authentic as the natural stones. Only with regular use can one identify the tangible worth of these gemstones. Fragile, susceptible to scratches and chipping at ends make hybrid gemstones a short term romance.

Even compared to the traditionally treat rubies, these hybrid gemstones start losing their sheen after a few years. But for imitation jewellery makers and fashion designers, these cheap hybrid rubies are perfect accessories.

With each passing year, there is a significant rise in demand for different types of natural gemstones. In 2016, the technology of cutting and polishing gemstones has reached a “never seen before” stage where new definitions and concepts are ruling the roost. 

If you are new to gemstone industry, and are exploring the world of assembling top grade gems, here are 4 terms you should know in 2016!

1. Opal doublets 

Also called the composite opals, opal doublets are actually two gemstones glued back-to-back using resins and glues. There could be an opal as one layer glued to other materials. Man-made doublets include a well-rounded off opal glued to black industrial glass or vitrolite.

The doublets are classified as primary opal gemstone or a secondary opal, depending on the thickness of the natural gemstone. Used in jewellery, opal doublets are very hard to distinguish from their natural counterparts. 

Opal doublet is given a cabochon cut for superior gem-like finish.

2. Opal triplets

Triplets are not as extensive as doublets. The triplet has three layers-

Black base 

Thin layer of natural opal (usually white opal)

Clear slice of quartz, glass acting as a capping

The difference in layering adds weight to the opal, without compromising on the clarity and translucency of the natural gemstone.

Compared to the doublets, opal triplets are cheaper but serve just the same purpose in jewellery making, especially considering the fact that natural opal gemstone is very fragile, and often chips away.

Note:

The doublets and triplets remain intact for years, if not decades, and hence give the opal a sense of durability for a longish use.

3. B Jade

Jade is a popular ornamental rock, and counted as a semi-precious gemstone. There are two distinct varieties of jade with similar silicate crystalline structure:

Nephrite

Jadeite

“B Jade” is an artificially treated jadeite that is bleached in acid and later doped with polymer resin to enhance its look. The B Jade family has a clear, spider-web like crystalline structure bearing a smooth apple green shade. The bleaching and subsequent impregnation process leaves absolutely no trace of spotting on the surface. 

In jade gemstone market, there are different categories:

A Jade: Bee-waxed jade with no artificial treatment or bleaching 

C Jade: Dyed B-Jade 

D Jade: Dyed Jadeite 

In 2016, the B Jade is back in popularity after revisions in technology and acceptance of polymeric doping as a regularised process in lapidary.

4. Lead-glass filling Rubies/ sapphires 

Also called composite ruby gemstone and sapphire gemstone, these are hybrid gemstones made using combination of lead-glass and corundum. Natural ruby is brown and hard, which makes them hard to cut. When combined with lead-glass, the ruby transforms into a clearer and brilliant gemstone that is easier to cut. In normal market, hybrid rubies can be as much as 35%! 

Though rated as one of the least accepted heat treatment process for ruby enhancement, lead glass filling clears up the impurities and the rutile silk structure is very much conspicuous. 

With the demand for natural gemstones putting immense pressure on the market, there have been resurgent rise of composite gemstones too. Called by many names in the industry, assembled gemstones or hybrids are not 100% natural material. They contain significant amount of man-made materials like glass, corundum, resin polymers and dyeing agents, but still command a position to reckon with. At least in the fashion and imitation jewellery industry assembled rubies, sapphires, emeralds and turquoise have a huge demand.

Let us dig a little about the hybrid or assembled rubies, sapphires gemstone and emerald beads.

Assemble gemstones: The definition 

An assembled gemstone is a combination of two or more materials. They could be singly natural or a blend of artificial and natural stones. For instance ruby and lead glass in Lead-glass filling gemstones. The commonly identified gemstones in the assembled categories are:

Doublets and triplets 

Inlays 

Mabe pearls 

Reconstructed, re-crystallized and restructured gemstones 

But is assembling really an alternative! Here are five popular reasons given by the manufacturers to give synthetic process a legitimate backing in the market.

Give the gemstone a greater durability making them more wearable as a daily use accessory

Boost the pricing and quality in terms of clarity, carat weight and fault filling 

Add desirable fillers and dyeing agents to make them more saleable 

Build a distinct family of gemstones that are hybrid, and not synthetic

Popular assemble gemstones

Doublets and triplet Opals

Without doubt, the doublets and triplets are popular as widely accepted hybrid gemstones. They are done exclusively for opals. White opal is used as a sandwich in triple layers, where the base is a black backing glass material, while the top surface is a translucent plastic that delivers a higher refractive index. 

Like a cementing, opal gemstones assembled as a doublet and triplets have the desired thickness and strength, without compromising on the lustre, refractive index, translucency and hardness.

Apart from the fragile gemstone like opal, lapis lazuli, black onyx, turquoise and quartz are other naturally extracted items cut into doublets and triplets for a fashionable market.

Mabe Pearls

Cultured pearls are susceptible to scratches and breaking. Mabe pearls are assembled gemstones using a blister dome cut apart from the mother shell. Mabe pearls can be attached back-to-back as if they look like a single wholesome pearl. 

Composite Hybrid rubies

Rubies and sapphires often carry a fault that requires filling. Fillers like dyeing agents, polymer resins and lead glass are used in the faulty gemstones. Use of composite materials as a filler occurs as an indistinct process where it is hard to detect the presence of unnatural material using unaided vision.

Point of caution:

Assembled gemstones can’t be cleaned and maintained like regular natural stones. Techniques like ultra-sound cleaning and laser treatment can affect the bond, giving rise to visible fault lines.

As a buyer, you must look for hints in the gemstone surface to distinguish the assembled gemstones from the real ones. From weight in carats to their clarity, there are many ways assembled gemstones catch the attention of usual buyers. 

If you are in the gemstone market, apart from the obvious colour and size, there is one more very important thing that you should evaluate. And nobody is going to cheat you on this if you know how to calculate the size of a gemstone. We all it- The Carat. When it comes to finding the right sized gemstone within a budget you can handle, carats is something you should get familiar with.

What is a carat?

Gemstones are weighed in carats. Every gemologist would count the carat as the basic factor to classify different gemstones. The raw pieces are cut into smaller and smoother edges. The finished gemstones are tagged with the carat after cutting to measure up the amount of wastage in the processing. 

Abbreviated to “ct” in a gemstone parlance, a carat is a unit of measurement usually represented in points. A point of a gemstone size is 0.01 of a carat or in general terms, one unit is 1% of what we know as a carat. For very small garnets, rubies and travertine, the usual unit of size determination is a “point” and not carats. 

Carat and pricing 

The word “carat” has same origin as that of the word “keratin”. Keratin is derived from the Latin word “keratos”, meaning “little horn”. The carob tree seeds are called keratin too, and the gemstones resemble them in more than one way that you can think of. Carats signify the uniformity of different sized gemstones. 

As far as pricing is concerned, a gemstone with higher carat value is quoted at a higher price. 

A correlation: Grams versus carat

Until the end of World War I, gemstones were still measured in grams and not carats. After 1920, the popularity of carats caught up owing to bigger sized diamonds being cut into cabochons and smaller shapes. As a method of approximation, gem scientists and lapidary artists zeroed on to carat as an international standard. 

One carat = 1/5th of a gram

In general term, one carat is 20 percent of what we know as gram weight.

Law of gemstone pricing

Price per carat is the universal factor to identify what the gemstone might be weighing. The pricing is fixed as per a very popular hand-rule called “Indian Law” or “Tavernier’s Law”.

In a bid to find the weight of the gemstone in terms of carats, the formula used is:

Carat = Facet style factor (ff) x {Girdle length (grl) x Girdle width (grw)} x depth (dep) x Average specific weight

These days, a specially designed digital scale is used to weigh precious gemstones. The same scale can derive the combined carat weight of more than one gemstone. 

To convert a gemstone’s weight in milligrams into carat, divide it with a factor of 200.

For example, if a diamond weighs 250 milligrams, the weight in carat is: 250/200= 1.25 ct

In terms of points, this carat value is equal to 125 points.

Apart from carat of course, there are three C’s you need to define to arrive at the right price- Cut, Clarity and Colour.