Opal,Cabochon 10.97 Carat

You have selected to learn about Utilizing the Gemological Institute of America Grading system

Due to the fact that our gemologists were trained at the GIA in the US, we use the GIA grading system. The GIA system is the only recognized universally used grading system for colored stones based on a scientific approach, thereby removing the subjectivity often encountered on the internet with color grades particularly.

You have selected to learn about ICA Member

We are a full member of the ICA (International Colored Gemstone Association) which is the largest and only worldwide body of its kind. It is a strict proponent of a stringent code of ethics to which we strongly abide. Click here to learn more

You have selected to learn about Gemstone ID Number

This particular gem’s ID number. It corresponds with the market based appraisal which accompanies the stone and the Personalized History and Ownership Report which becomes available in the online membership account of clients who purchase gemstones from us.

You have selected to learn about Barcode

One of the security features on the certificate.

You have selected to learn about Gemstone Species and Variety

We will address the categories of Gemstone Variety and Species together. All gemstones have a scientific nomenclature allocated to them. Gemologists refer to gemstones using this nomenclature. A gemstone first belongs to a Species in the gem kingdom, just as different animals and insects do in the animal kingdom, then they have a variety name allocated to them within that species. For example, Tanzanite belongs to the species Zoisite, Ruby and Sapphire to the Species Corundum, Aquamarine to the species Beryl and so on. Within each species, each different stone has a variety name allocated to it. So in the examples above, Tanzanite is the blue variety of the species Zoisite, Ruby is the red variety of the species Corundum whilst Sapphire is the blue variety of the species Corundum. Aqumarine is the blue variety of the species Beryl whilst Emerald is the green variety of the species Beryl. When testing gems, each species has clearly defined physical and chemical characteristics which gemologists can identify using gemological equipment. These clearly and positively identify a particular gemstone as a member of its particular species.

You have selected to learn about Gemstone Species and Variety

We will address the categories of Gemstone Variety and Species together. All gemstones have a scientific nomenclature allocated to them. Gemologists refer to gemstones using this nomenclature. A gemstone first belongs to a Species in the gem kingdom, just as different animals and insects do in the animal kingdom, then they have a variety name allocated to them within that species. For example, Tanzanite belongs to the species Zoisite, Ruby and Sapphire to the Species Corundum, Aquamarine to the species Beryl and so on. Within each species, each different stone has a variety name allocated to it. So in the examples above, Tanzanite is the blue variety of the species Zoisite, Ruby is the red variety of the species Corundum whilst Sapphire is the blue variety of the species Corundum. Aqumarine is the blue variety of the species Beryl whilst Emerald is the green variety of the species Beryl. When testing gems, each species has clearly defined physical and chemical characteristics which gemologists can identify using gemological equipment. These clearly and positively identify a particular gemstone as a member of its particular species.

You have selected to learn about Refractive Index

All minerals reflect light to a different degree. When light enters a gem from some other medium it normally changes its speed and direction of travel. This is refraction. To express the magnitude of the change gemologists use refractive index which is how many times as fast light travels in air as it does in the gem. Tanzanite for example has an RI of 1.69 which means light travels 1.69 times faster in air as it does in Tanzanite. The slower light moves through a gem the higher the gem’s RI. The refractive index of a gem is measured by gemologists using a Refractometer and RI liquid and is considered to be the most constant and reliable gem property a gemologist can test which is why it is included on the certificate.

You have selected to learn about Treatments

Gem treatment might be defined as any human controlled process that improves the appearance, durability or value of a gem. Treatments can be divided into a few basic categories – temperature, irradiation, chemicals or surface modification. Using high temperature to change the appearance of a gem is known as heat treatment and is one of the oldest and most common treatments dating back to 2000BC. Several gem types are routinely heated in the trade and the treatment is accepted as permanent and stable. For gems such as Tanzanite and Aquamarine, the treatment is applied to virtually 99.9% of all production and is considered normal.

You have selected to learn about Origins

This refers to the gem’s origin. In some cases, as with Paraiba Tourmaline, Burmese Ruby, Kashmir Sapphire, the stone’s origin can mean a premium price. Mostly, however, this is not the case and gems are graded, sold and admired on their own merit. Origin is an important category on a gem certificate though as it basically refers to its "place of birth".

You have selected to learn about Dimensions

These are the measurements of a gem usually taken in millimetres. They are stated with length first, width second and depth third. Our gems are measured using a digital guage for extreme accuracy.

You have selected to learn about Weight

Weight in gems is measured in carat. One carat is equal to 1/5th of a gram and the term is derived from the early days of gem trading when the seeds of the Carab tree were used as counter measures to weigh gems as carab seeds are always uniform in weight. Not to be confused with “karat” which is a ratio and a term used to refer to gold.

The carat weight of a gemstone is one of the 4 C’s and hence an important value indicator in its own right. Generally speaking, the higher the carat weight the rarer the gemstone as it exponentially more difficult to come by clean, top color large gem crystals than it is small ones. That is why, with most gems, you will see an increase in price per carat as the carat weight increases in the same quality bracket. Notable examples are Tsavorite, which is very rarely found in high qualities in sizes above 2 carat, hence per carat prices leap more steeply than with many other colored gemstones.

You have selected to learn about Shape

This refers to the shape or cut of the gemstone. Generally speaking, no one particular shape is considered more valuable than another as gems are cut into the shape that their rough state best dictates in order to retain the most weight in the cutting process. However, occasionally, some sellers will sell more wasteful cuts such as trillions at a premium. We do not subscribe to this practice and all shapes are priced on a par. The exception to the rule is matched pairs. Usually in order to cut a matched pair weight is deliberately lost in order to bring both stones to the same dimensions. This is why matched pairs generally command a 20% premium in the marketplace.

You have selected to learn about Clarity Type

The GIA grades clarity in transparent, faceted colored stones using a series of definitions which state the typical inclusions and their appearance in each grade. The typical clarity of a given kind of colored stone depends largely on its mode of formation. Different gems can be very different in typical occurrence and they clearly cannot be graded in exactly the same way. The ground rules have to be slightly different. Some colored stones like Aquamarine and Tanzanite are expected to be relatively free of inclusions. Others like Ruby and Tsavorite are acceptable with minor inclusions. And some like emerald, may have numerous inclusions or inclusions very obvious to the unaided eye and still be desireable. To clarity grade emeralds on the same scale as Aquamarines would almost automatically put all Emeralds in the lowest clarity grade. To balance fairness and workability, the GIA divides all transparent colored stones into 3 broad categories or Clarity Types. Each Type is based on the inclusions generally expected to be seen in stones in the market.

TYPE 1 - Stones that are often virtually inclusion free. Include Aquamarine, Tanzanite, Topaz
TYPE 2 – Stones that usually contain inclusions. Include Ruby, Sapphire, All Garnets, Spinel, Tourmaline
TYPE 3 – Stones that are almost always included. Include Emerald, Red Tourmaline
There is a subtly different set of clarity grade definitions for each type

You have selected to learn about Clarity Grade

Gems are graded under 10x magnification. The GIA clarity grades are VVS / VS / SI1 / SI2 / I1-3 / Dcl. Colored stones are not graded by the GIA as flawless or internally flawless, even if they are. This is because a rigid definition of the flawless grade for diamond grading has become established in the trade bolstered by clear FTC guidelines and the vast majority of colored stones simply cannot measure up to these strict definitions for the highest grades of Diamonds. In Type 1, a colored stone that would grade flawless in the diamond sense may sometimes be found perhaps in Aquamarine or Tanzanite but very unusual as virtually any minute inclusion or blemish would disqualify it. Diamonds are graded much more strictly than colored stones as they are harder.

GIA grades are applied to each of the 3 gem types differently (to understand what constitutes a gem type click on the "Clarity Type" category on the certificate.

GIA Clarity Grades as applied to Type 1 Gemstones:

VVS : Characterized by minute inclusions which are difficult to see under 10x and invisible to the unaided eye. Even under a 10x a VVS stone might appear to be flawless. Typical inclusions may be pinpoints, very fine needles.

VS : Characterized by minor inclusions which are somewhat easy to see under 10x but usually invisible to the unaided eye. Typical inclusions might be small included crystals, liquid inclusions, numerous fine needles, small fingerprints

SI1-SI2 – Characterized by noticeable inclusions which are apparent under 10x and in SI1 usually visible and SI2 quite visible to the unaided eye. Inclusions normally have low relief. Typical inclusions may be included crystals, large fingerprints, chips, feathers, dens clouds.

I 1-3 – Characterized by inclusions that have a negative effect on either appearance or durability or both. Inclusions are often large and prominent to the unaided eye and there amy be noticeable loss of transparency.

Dcl – Declasse – Characterized by inclusions so numerous the entire stone is no longer transparent but translucent at best. Dcl stones lack beauty and durability.

GIA Clarity Grades as applied to Type 2 Gemstones:

VVS : Characterized by minor inclusions which are somewhat easy to see under 10x but usually invisible to the unaided eye. Typical inclusions might be small included crystals, liquid inclusions, numerous fine needles, small fingerprints

VS : Characterized by noticeable inclusions of moderate size, which are easy to see under 10x and sometimes visible to the unaided eye. They are still non damaging. Typical inclusions are liquid inclusions, fingerprints small chips, small feathers, clouds.

SI1-SI2 – Characterized by obvious inclusions which are large and/or numerous under 10x and in SI1 apparant and SI2 very apparent to the unaided eye. Typical inclusions may be large included crystals, large chips, feathers, dense clouds.

I 1-3 – Characterized by inclusions that have a negative effect on either appearance or durability or both. Inclusions are often large and prominent to the unaided eye and there amy be noticeable loss of transparency.

Dcl – Declasse – Characterized by inclusions so numerous the entire stone is no longer transparent but translucent at best. Dcl stones lack beauty and durability

GIA Clarity Grades as applied to Type 3 Gemstones:

VVS : Characterized by noticeable inclusions which are easy to see under 10x but usually invisible to the unaided eye. They are still non damaging. Typical inclusions are small included crystals, liquid inclusions, fine needles, small feathers, clouds.

VS : Characterized by obvious inclusions which are very easy to see under 10x but and often visible to the unaided eye. Typical inclusions are small included crystals, liquid inclusions, chips, fine needles, small feathers, clouds.

SI1-SI2 – Characterized by prominent inclusions which are large and numerous under 10x and in SI1 apparant and SI2 very apparent to the unaided eye. Typical inclusions may be easily visible but not extensive feathers and dense clouds.

I 1-3 – Characterized by inclusions that have a negative effect on either appearance or durability or both. Inclusions are often large and prominent to the unaided eye and there amy be noticeable loss of transparency.

Dcl – Declasse – Characterized by inclusions so numerous the entire stone is no longer transparent but translucent at best. Dcl stones lack beauty and durability

You have selected to learn about Color Grade

Color is the main indicator of value in colored gemstones and is the most important of the 4C’s. The GIA has a sophisticated color grading system which is the most advanced and only non subjective system yet developed. The GIA Color Grading system describes color in terms of 3 dimensions — Hue, Tone and Saturation.

HUE is the basic impression of color that we notice immediately. A gem usually has several hues in it and hence it is given a dominant hue and a modifying hue. The vB you see in this example stands for a modifying hue of blue and a dominant hue of violet. Thus the stone is a violetish Blue.

TONE is the lightness of darkness of a color sensation. The GIA divides tone into 11 steps from colorless or white through increasingly darker grays to black. The GIA uses 7 of these steps in grading tone in transparent colored stones.

• 2: very light (hue)
• 3: light (hue)
• 4: medium light (hue)
• 5: medium (hue)
• 6: medium dark (hue)
• 7: dark (hue) 8: very dark (hue)

The optimum range with most gemstones is 4—7 where the stone is neither too light or too dark. SATURATION is the strength, purity or intensity of the hue. It is assessed on a 7 level scale (0 through 6)

• 1: brownish/grayish (hue)
• 2: slightly brownish/grayish (hue)
• 3: very slightly brownish/grayish (hue)
• 4: moderately strong (hue)
• 5: strong (hue)
• 6: vivid (hue)

As color can be the most complicated and difficult to understand of the GIA grades, we have developed a set of charts which will help you better understand tones and saturations as they apply to a particular gem type:

Click Here to see the Tanzanite Tone and Saturation Chart

Click Here to see the Tsavorite Tone and Saturation Chart

Click Here to see the Aquamarine Tone and Saturation Chart

Click Here to see the Malaia Garnet Tone and Saturation Chart

Click Here to see the Rhodolite Garnet Tone and Saturation Chart

Click Here to see the Yellow Sapphire Tone and Saturation Chart

You have selected to learn about Photograph

The actual photograph of the gemstone in question taken in white daylight spectrum.

Photographs are of the actual gemstone represented and are not enhanced in any way.

You have selected to learn about Graduate Gemologist

Our certificates are graded by GIA Graduate Gemologists and signed by our Chief Gemologist. The GG Degree is the most coveted and respected of the qualifications in the Gemology arena. It is recommended that when dealing with a gem company they should have GG’s on staff in order to ensure accurate gem identification and representation. Click here to verify our Chief Gemologists GG status on the GIA Worldwide directory.

You have selected to learn about Tamper Proof Hologram

One of the security features of the document. If tampered with the hologram will denature and spoil hence indicating that the document has been tampered with.