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Ruby Education



Before purchasing a gemstone, whether it is a ruby, sapphire, emerald or any other gemstone it is important to understand the components that determine its value. There are various components that help determine the value for a gemstone such as its color, clarity, weight, treatment etc... Below we have mentioned all of the components affecting a gemstone's value. You may click on 'read more' for any of the components for detailed analysis and for our grading structure for the relevant component. If you would like to speak to a gemologist for any questions you may have, please contact us during our normal business hours at (888) 436-7692.


In ruby, sapphire, emerald and other gemstones color is the main criteria in determining its value. Most individuals when they inquire about ruby, sapphire and emeralds, they expect these precious gemstones to have similar color grading system as diamonds. Unfortunately, there is no standardized system that is used to derive the value of these gemstones. There is a good reason for this as is explained below.

The reason is simple: Gemstones such as Ruby, Sapphire & Emeralds have many unique colors, tones and hues which are numerous in quantity. Also, to make a judgment that which color, tone or hue is better is subjective and depends on who is observing the gem. Meanwhile, in diamonds it is very clear and straightforward to judge its color. Diamonds are graded on the basis of how colorless it is and not graded on tone, saturation or the type of color. In fact, this degree of colorless can now be traced by computers and thus a lot of the highly reputable laboratories use computers to grade the color of diamonds.

However, in gemstones such as ruby, sapphire and emeralds, it is not possible to do this. In gemstones there are three aspects of color which have to be evaluated: a) Color purity b) Saturation of color c) Color Hue . The issue in hand is that color interpretations of gemstones are unique and reflect the personal preference of an individual and thus there is no way of accurately determining which nuance of color or the type of saturation of color is superior to another. As a result, due to the many variations of color purity, color tones and hues and the difficulty in determining which variation is superior it is impossible to come up with a standardized system of grading color for gemstones.

GemsNY uses its own terminology to define various types of colors that exist among sapphires, rubies and emeralds.

So What Is The Right Color Grade For You?

Common sense and your subjective preferences in color will be the ultimate guide in choosing the right color. Something that looks very beautiful to you is most likely to appeal to other people as well, as people tend to have generally similar opinions in what shades of color seem to be nicer than others. As we have been selling sapphires for over 20years, we know that sapphires which are too dark and look more black than blue are going to be significantly cheaper than stones which are nice medium intense blue and have very good brilliance. This is how prices are set in the industry as well, the color shades which are more appealing to the general public are going to cost more than stones which are not.


Gemstones are scrutinized far less severely for clarity than diamonds. In ruby, emeralds and sapphires and all other gemstones the main criteria is whether it is eye clean or not. Eye clean means that to the observer by just viewing the gem with their naked eyes they cannot locate any inclusions in it. Gemstones generally have far more inclusions than diamonds do and thus it is not required to use a 10x magnification as is used for diamonds. The value of ruby, sapphire and emeralds is affected by how eye visible the inclusion is but there is very little difference in the price between stones which are eye clean and stones which have no inclusions visible even under 10x magnifications. In diamonds color, clarity, carat weight and cut play an equal part in determining its value. However, for emerald, ruby and sapphires color plays a significantly bigger role in determining its value than clarity does

Keeping the above concepts in mind for clarity we have developed our own clarity grading system where the highest value which is "Flawless" represents a gemstone where no inclusions are visible to a trained gemologist in any part of the gemstone without using magnification. The lowest grade is "I3" which represents an included gemstone where the inclusions hinder the brilliance and color of the gemstone. Below is the detail clarity grading system that GemsNY uses for grading its rubies, sapphires and emeralds, along with a description of each:

FL,IF- Flawless or Internally Flawless.This is the highest clarity grade a gemstone can have. This means the gemstone is 100% clean to the eye to a trained, experienced gemologist but not necessarily under 10X or higher magnification.

VVS1, VVS2- Very Very Small Inclusions.This grading means the gemstone would be 100% eye clean to an untrained eye but a gemologist might be able to observe very, very tiny inclusions from certain side angles.

VS1, VS2- Very Small Inclusions.This means very tiny inclusions would be visible under very close inspection to an untrained eye.

SI1, SI2- Small Inclusion. Slight visible inclusions upon inspection would be visible to an untrained eye but inclusions are not affecting the brilliance or the color in the gemstone.

I1,I2,I3-Imperfect.These gemstones are highly included where the inclusions hinder the brilliance and color of the gemstone.

So What Is The Right Clarity Grade For You?

The most important criteria to look for is if the gemstone you are looking to purchase is eye clean or not. Unlike diamonds, the value of gemstones is not significantly affected by its clarity, unless the gemstone has big crystal in the center of stone which is very visible. So we would say if you are picky in terms of clarity then you should stay with VS1 clarity or higher. These gemstones have very minute inclusions which are almost impossible to see without magnification. If you want to save some money then VS2 and SI1 clarity gemstones are ok as well as you will be able to save money and still get a gemstone which is relatively eye clean.


Cut grading is very similar to clarity grading for gemstones in that it plays much less of a role in a value of a gemstone than it does for diamonds. Few main points to note about cut are: Firstly, there are many more number of shapes and cutting styles available in diamonds than gemstones. It would be very difficult to list them all. Secondly, gemstones such as ruby, emerald and sapphire are cut to retain the most color (as that is the number one variable in determining gemstone price) and are not cut to precision like diamonds. It would be unrealistic to expect a gemstone such as ruby or sapphire to be as well shaped and be cut to precise proportions as a diamond. However, one thing to note here is that unheated stones generally will have much poorer quality of cutting than heated stones because cutters are more inclined to yield as much carat weight as possible from the unheated rough than from the heated rough where some attention is still paid on the cutting of the stones.

Carat Weight

Carat weight is the unit of measurement that is used by the jewelry industry to weigh gemstones. One carat is equal to .2 grams or there are five carats in one gram. Here is a chart which provides an idea of how large a particular weight, well-cut round ruby, emerald or sapphire looks like:

Choose A Carat Weight
1/4 1/3 1/2 3/4 1 1
2 3 4 5

As you can see, a 2-carat ruby is not twice as big as a 1-carat one. Also, the price per carat of a 2-carat ruby or other gemstone is significantly more than a 1-carat, assuming both gemstones are of the same quality in all other aspects. The reason for this is simple: A two carat ruby or sapphire is much rarer than a one carat one and thus it is more valuable than a 1-carat ruby or sapphire.

Important Note on Carat Weight among different gemstones

One important point to note is that a 1carat sapphire or ruby doesn’t physically look as big as a 1carat diamond. The reason? Is specific gravity. Ruby and sapphires are much more dense then a 1carat diamond. Look at the chart below for details:

Gemstone Name Specific Gravity Mohs Hardness
Diamond 3.51 10
Emerald 2.63-2.91 7.5-8.0
Ruby 3.96-4.05 9.0
Sapphire 3.96-4.05 9.0

As you can see ruby and sapphire are about 20% more dense then a diamond and when you add in to the fact that they are not cut to exact proportions like diamonds the visual difference is generally close to 30%. So that means a 1carat diamond would look similar to a 1.30ct ruby or sapphire. In other words, the measurements of a 1carat diamond round are 6.5mm and to have a 6.5mm ruby or sapphire you would need to find a stone which is closer to 1.30cts. However, for emeralds, since they have much lower specific gravity than diamonds but are not cut to as exact proportions as diamonds, will generally have the same look as a diamond for a given carat weight. So a 1carat diamond and 1carat emerald will both have measurements which will be approximately 6.5mm.

Furthermore, not all 1carat rubies, sapphire, diamond or emerald will look the same. The main reason is that not all stones are cut the same. Some stones are very shallow (meaning depth proportion is less compared to the length and the width) and thus will have a much bigger face or vice versa. For example, a one carat emerald round will generally have 6.5mm diameter because generally for such stones the depth percentage is close to 70% (or 4.55). However, if a stone is shallow and has depth percentage of 60% (3.9) width, the diameter will be closer to 7mm. The emerald which is shallow will appear 15% larger from the top than the other emerald even though they both weigh the same.

Firstly, the right question should be what measurements are right for her? As we have seen above based on the type of gem and the way its cut, the physical size from the top (or the face up view, also known as the crown' of the stone in gemology) will vary. Now to evaluate, what measurements are right for her will require one to understand her preferences better. Here are few suggestions:

  • The type of jewelry she currently wears is a great indicator of her likings.
  • Try in covert ways to find out her preferences without her suspecting anything.
  • Ask family members. Ask her sister, mother, cousin or a close friend to understand her likings better.
  • Ring size can be an indicator of the type of ring and the gemstone size to choose. Generally somebody who has very thin fingers and is a ring size 3.5, will not prefer rings with very large gemstones (like a 5carat size sapphire which measures 11mm). However, everybody has different preferences, so this option should be used as a last resort.


There are various types of treatments in gemstones like rubies, sapphires and emeralds. We list few of the main treatments here and provide information on what is accepted and what isn't. Please note that the treatments listed here are only of which apply to Ruby, Sapphire & Emeralds. Also, the definitions of the treatments is taken from the AGTA (American Gem Trade Association) which is considered the highest authority in gemstone treatments, gemstone testing and in general gemstone issues concerning the gemstone jewelry trade.

Heat Treatment:

Among rubies and sapphires it is a general practice among the manufacturers to bake the rough in order to enhance the color of the gemstones. This treatment has been there in the industry for a long time and is accepted worldwide and industry wide as a PERMANENT treatment. In fact, this treatment is so common that in the trade if an individual asks for a ruby or sapphire it is understood they want heated. Probably over 99% of all Rubies and Sapphires used in today's jewelry are heated. This is a cheaper alternative to unheated ruby and sapphires which are far more expensive and more difficult to find. This treatment is not found in emeralds.

GemsNY Recommendation:

There is no right or wrong answer to this question. The answer depends on two main factors: personal preference and the budget set aside for the purchase. For further details please click here


In this treatment there is coloring material introduced into the gemstone to improve the color appearance or to change the color all together. This treatment is rare in rubies and emeralds and doesn't apply to sapphires. GemsNY doesn't carry any rubies, emeralds or sapphires with this treatment and doesn't recommend purchase of any gemstones with this treatment because it is very unstable and comes out if exposed to some household chemicals such as bleach.


In this treatment gemstones are filled with foreign substance, including glass, to cover surface cavities and fractures. This treatment is common in rubies and emeralds and is not applied on sapphires and the stability of it is generally very good. GemsNY carries rubies with filling as they offer much better value for the consumer and the treatment is also quite stable, on the most part and will not come out very easily. A large percentage of the rubies in the market today have this treatment as this is done in conjunction with the heating process. GemsNY doesn't carry filled emeralds.


In this treatment there is a use of chemicals in combinations with high temperature to produce artificial color change among gemstones. This treatment is very rarely found among rubies but is more common among sapphires and emeralds. GemsNY doesn't carry any diffused rubies, emeralds or sapphires as we consider this treatment to be too severe.


Gemstones which are unheated have only traditional process of cutting and polishing applied to them in order to improve the appearance or durability of the gem. Unheated sapphires are rare and unheated rubies are extremely rare (especially in 3ct and bigger size). All GemsNY unheated gemstones are mostly certified by GIA or other highly reputable independent laboratories.

Cedar Oil:

This treatment is only conducted in emeralds. Among emeralds it is a general practice among the manufacturers to oil the emeralds to enhance the color of the gem. This treatment has been there in the industry for long time and is accepted worldwide. In fact, this treatment is so common that in the trade if an individual asks for an emerald it is understood they want oiled emerald. Probably over 99% of all emeralds used in today's jewelry are oiled.

So Which treatments should you be willing to accept, if any at all?

GemsNY Recommendation:

For rubies and sapphires, we would recommend untreated stones as they offer the best investment. However, if you are on a budget, like most people, it would be better to go with a heated gemstone which will be significantly cheaper and thus allow you to purchase either better quality or a bigger size gemstone than you would have otherwise gotten in an untreated stone. Also, gemstones with filling should also be considered as cheaper alternative to heated rubies (This treatment doesn't exist in Sapphires as of now). Rubies which are filled can offer tremendous value as they are significantly cheaper than regular heated rubies and can allow you to purchase larger size rubies which otherwise might not have met your budget.

For emeralds, cedar oil is a standard treatment within the jewelry trade. GemsNY recommends cedar oil treatment as stones without oil treatment are extremely, extremely rare and very expensive. 99.9% of all emeralds in the market are oiled which means for every one unoiled emerald there are thousand oiled emeralds in the marketplace.


There are various gem laboratories out there providing their own independent judgments on gemstone specifications. Unfortunately, often these laboratories vary in their strictness in grading of the gemstones. One has to be skeptical in particular when the lab providing the certification is the same lab selling the item, as there is a conflict of interest. For this reason, all of GemsNY gemstones over $1000 in value come with independent lab certifications. Below we list and provide details on only the most respected and well known laboratories:

UGL - Universal Gemological Laboratory

UGL is located in New York City in the jewelry district. Their strength is to provide detailed appraisals and certificates for gemstone jewelry. They have been in business for over 15years. UGL is the only lab which uses a standard grading system for emerald, ruby and sapphires. Also unlike GIA, which is the largest lab in the world for diamonds and gemstone certification, they provide both certificates and appraisals using their proprietary grading system.

GIA - Gemological Institute of America

GIA is the largest and most reputable lab in the world. There is no lab in USA which is even a close second in terms of certification for gemstones and diamonds. Only drawback with GIA is that they don’t provide appraisals for loose gemstone or finished jewelry.

GRS - Gem Research Swisslab

GRS is also one of the leading gemstone grading laboratories and is one of the most commonly used labs for gemstone jewelry and loose gemstones. In Asia and Europe, the two of the most prominent labs are GIA and GRS for gemstone certification.

TGL - Tokyo Gem Laboratory Co., Ltd.:

TGL is also a leading gemstone grading laboratories and is also used very commonly in the jewelry trade around the world. This laboratory has various branches all around the world. This is one of the labs GemsNY prefers.

EGL gemstone certificates are used occasionally in the trade. This lab is known more for diamonds certifications than gemstones.

IGI- International Gemological Institute

IGI is used heavily by large retailers such as Macys. IGI again is a second tier lab used for diamond grading primarily and their grading are definitely much more lenient then GIA.


GemsNY's high tech in-house gemology laboratory uses similar state of the art technology used by some of the most renowned laboratories such as GIA, GRS and TGL. We are so confident of our gemstone grading that we provide a full 100% money back 30 day guarantee.


Rubies, Sapphires and Emeralds come from various different mines over the world. The origin of these gemstones has an impact on their prices. Burmese ruby and sapphire and Ceylon (Sri Lanka) sapphires are considered one of the finest in the world and same could be said for Colombian emeralds.

While emerald, ruby and sapphires come from variety of different origins, we have listed below the main sources for each gemstone:

Blue Sapphire Origins
Kashmir This is considered the best mine for sapphires but all natural Kashmir sapphires mines have been exhausted and thus no new Kashmir sapphires are mined in nature.
Ceylon Ceylon is another name for Sri Lanka. Sapphires from this mine are extremely rare and are of very high quality. These rare stones generally have very good to excellent brilliance and a pleasant blue color.
Burmese Burmese sapphires are known to offer very nice royal blue color but generally will not offer excellent brilliance. Most stones have good to very good brilliance.
Madagascar These sapphires are very similar to Ceylon sapphires in terms of quality. They offer excellent brilliance and vivid blue color.
Kancha Kancha is short name for location called Kanchanaburi which is in Thailand. Sapphires from this mine are rare and generally have a pleasant navy blue or royal blue color.
Australian Australian sapphires are of generally commercial grade. Sapphires from this mine are used in significant amount of world's sapphire jewelry and are generally midnight blue in color and have fair to good brilliance.
Emerald Origins
Colombian These are considered the best quality emeralds. Such emeralds are known for having exceptional brilliance.
Zambian Such emeralds are rare and are known to have deep foresty green color.
Brazilian Brazilian emeralds offer a fine deep green color but at least in the lower end tend to be heavily included.
Ruby Origins
Burma These are considered the highest quality rubies as they offer a true red color in the higher end.
Madagascar These rubies tend to be orangish red but generally have excellent brilliance.
Thai These rubies generally have a heavy purplish undertone. GemsNY doesn't carry thai rubies.
Tanzania Such rubies tend to be a orangish and purplish red but generally have excellent brilliance.

Note on Origin Determination by Laboratories

Many of the laboratories will claim that they can precisely determine the origin of ruby, emeralds and sapphires but it is our repeated experience that different laboratories have given different origin of the same gemstone and both are very reputable laboratories! Who is right and who is wrong? Also, the most prestigious laboratory in the world, GIA (Gemological Institute of America) refuses to guarantee their origin findings. GIA states: Any statement on geographic origin is an expert opinion based on a collection of observations and analytical data. What we can conclude from this is that GIA doesn't want to provide authoritative statements on origin as they view origin findings as an educated guess rather then confirmed findings. Furthermore, most of the other laboratories file a 'origin' disclaimer on the back of there reports, where they clearly state that they can't be held liable for errors in their decision.

GemsNY Recommendation

In conclusion, GemsNY strongly believes, due to all these ambiguities, to put little faith on the origin of the stone and pay closer attention to which gemstone is more visually appealing to you. Rubies which are certified Burmese are somehow worth a lot more than Madagascar stones and Sapphires which are certified Kashmir are somehow worth thousands more than a Sapphire of any other mine. The origin of our gemstones that we provide on our site is evaluated to the best of our ability by using our decades of experience along with intensive testing. Also, we use the location and the manufacturer who we purchase from as a strong factor in determining its origin.

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