emology Education

1.creating the D-to-Z color scale and Flawless-to-I3 clarity scale for diamonds
2.detecting irradiated yellow diamonds
3.determining the color of black cultured pearls to be natural
4.the first study of a new gem now known as tanzanite
5.the first report on faceted synthetic diamonds
6.identifying Naturl rubies, sapphire ,all type Gems & all type Rudraksha.
7.identifying glass-filled rubies & Gems
8.identifying synthetic & Plastik rubies , Gems & Rudraksha
9.detecting fracture-filled diamonds
10.evaluating the durability of emerald filling substances
11.distinguishing natural from synthetic diamonds
12.detecting synthetic moissanite, a popular diamond imitation
13.identifying the effect of fluorescence on diamond appearance
14.detecting diamonds decolorized by high pressure/high temperature (HPHT) treatment
15.detecting gem-quality synthetic diamonds created by chemical vapor deposition (CVD)
16.creating a comprehensive system for grading diamond cut quality.
17.Specific gravity , Refractive Index , Lustre ,Hardness ,Species ,Chemical , Hardness,
     Growth lines , Inclusions , Other characteristics Identify.
 


How Grades Diamonds
People from all over the world send their diamonds to the Laboratory for grading and analysis.



Grading Diamonds

Anonymity
Objectivity and independence are the hallmarks of all RJL reports and services, and RJL has elaborate processes in place to ensure a diamond anonymity through the grading process.

Weights and Measures
Diamonds are weighed with an electronic micro-balance that captures their weight to the fifth decimal place.

Grading Cut
verify & Grading cut


Grading Color
Since light source and background can have a significant impact on the appearance of color, the diamond color is graded in a standardized viewing environment. Color graders submit their independent opinions into the system.

Grading Clarity and Finish
Clarity is graded with 10x magnification under standard viewing conditions. The preliminary grader carefully examines the diamond to locate clarity/finish characteristics and evidence of any diamond treatments, such as fracture filling or laser drilling.

Depending on the diamond weight, quality, and the agreement of grading opinions, additional quality assurance process steps are also performed. More experienced staff gemologists may review all of the previous grading information and render independent clarity/polish/symmetry opinions. Grading results are finalized once there are sufficient agreeing opinions.

----------------------------------------------------------------------------------------------------

Grading Scale

While diamonds are graded using the system devised by the Gemmological Institute of America (GIA) in the 1950s, there is no standardized or universally accepted grading system for colored stones like rubies, sapphires, emeralds, etc. Historically, it has always been a general practice to grade colored stones with the unaided eye. However, we have devised a grading scale, on the basis of the diamond grading scale, which is easy to understand and not only takes into consideration appearance with the naked eye but also the appearance under 10x magnification (i.e. a jeweler's loupe).

 

CLARITY GRADING SCALE

Detailed Clarity Grading Scale on the Basis of which the Colored Stones listed in our store are graded (the first one being the best and the last one being the lowest grade)

Grade

Eye-Clean / Loupe-Clean (10x)

Detailed Description

IF (Internally Flawless)

Eye-Clean, Completely Loupe-Clean

No inclusions visible under 10x Magnification

VVS1 (Very Very Slightly Included 1)

Eye-Clean, Loupe-Clean

Minor Pin-Point Inclusions visible under 10x Magnification

VVS2 (Very Very Slightly Included 2)

Eye-Clean, Loupe-Clean

Minor Pin-Point Inclusions visible under 10x Magnification

VS1 (Very Slightly Included 1)

Eye-Clean, Near Loupe-Clean

Minor Inclusions visible under 10x Magnification

VS2 (Very Slightly Included 2)

Eye-Clean, Near Loupe-Clean

Minor Inclusions visible under 10x Magnification

SI1 (Slightly Included 1)

Eye-Clean, Not Loupe-Clean

Inclusions visible under 10x Magnification but not with unaided eye

SI2 (Slightly Included 2)

Near Eye-Clean, Not Loupe-Clean

Inclusions visible under 10x Magnification and also with unaided eye (minor)

SI3 (Slightly Included 3)

Not Eye-Clean, Not Loupe-Clean

Inclusions visible under 10x Magnification and also with unaided eye (considerable)

I1 (Included 1)

Visibly Included

Inclusions visible under 10x Magnification and also with unaided eye (heavy)

I2 (Included 2)

Visibly Included

Inclusions visible under 10x Magnification and also with unaided eye (very heavy)

Semi-Transparent

Varies from stone to stone

Not Completely Transparent neither Completely Translucent

Milky-Transparent

Varies from stone to stone

Transparent but with milkiness

Translucent

Varies from stone to stone

Allowing light to pass through but not transparent

Opaque

Varies from stone to stone

Not allowing light to pass through

Note: The numbers denote the intensity of inclusions i.e. the intensity of inclusions in a stone with VVS2 clarity would be more than those in a stone with VVS1 clarity.

 

GENERAL GRADING SCALE

Gemstones are also graded on a scale from “A” to “Z” by our gemmologists based on the overall appearance and after taking into consideration the combination of the following criteria:

  1. General Rarity
  2. Clarity Grade, intensity of inclusions and effect of inclusions on the overall appearance of the stone
  3. Hue, Tone and Saturation of Colour
  4. Cutting Grade
  5. Origin
  6. Appearance of the gemstone in relevance to the general appearance of stones in that particular group

This is a general grading scale which divides all gemstones into  parts depending on a variety of factors. A Majority of the stones listed on the store are grade “A” and grade “B” stones since we list very few grade “C’, “D” , “E” stones etc.

 

Also See: Gem Certification

----------------------------------------------------------------------------------------


  Gem Testing Reports
Gemological Identification Reports assess the characteristics of a Astro-Gem (weight, shape-cut ,Transparency,Lustre, Refractive Index,Specific gravity , Hardness ,Species, Inclusions and color) and indicate any detectable treatments. The stone’s identity, whether it is natural or synthetic, and if it is a ruby, sapphire or emerald ect., geographic origin is provided. 

  Gem Identification Reports

These reports document the results of a full gemological examination of a material, identifying the material examined and detailing such characteristics as color, transparency, shape, cut, and dimensions weight . The full report states whether the material is natural or synthetic and if it has been treated to enhance its appearance by an identifiable treatment. The report also notes whether the material is a simulant with no known natural counterpart, or if it has been assembled from two or more separate components.

 

Gemstone Name

  Specific    Gravity

     Mohs Hardness

    Index of Refraction

    Gemstone Family

Achorite

3.03 - 3.25

7.0 - 7.5 Mohs

1.610-1.661

Tourmaline

 

Agate

2.65

7.0 Mohs

1.530 - 1.550

Quartz

         

Almandine

3.50 - 4.30

6.5 - 7.5 Mohs

1.750 - 1.830

Garnet

Almandine Spinel

3.58 - 4.06

8.0 Mohs

1.708 - 1.735

Spinel

Almandine-Spessartine

3.50 - 4.30

6.5 - 7.5 Mohs

1.750 - 1.830

Garnet

   
 Amethyst

2.65

7.0 Mohs

1.532 - 1.554

Quartz

Andradite

3.50 - 4.30

6.5 - 7.5 Mohs

1.880 - 1.940

Garnet

Aquamarine

2.63 - 2.91

7.5 - 8.0 Mohs

1.567-1.590

Beryl

Balas Ruby

3.58 - 4.06

8.0 Mohs

1.708 - 1.735

Spinel

Black Opal

1.98 - 2.25

5.5 - 6.5 Mohs

1.440 - 1.460

Opal

Bloodstone

2.65

7.0 Mohs

1.535 - 1.539

Quartz

Brazilian Emerald

3.03 - 3.25

7.0 - 7.5 Mohs

1.610 - 1.640

Tourmaline

Cairngorm

2.65

7.0 Mohs

1.540 - 1.550

Quartz

Carnelian

2.65

7.0 Mohs

1.530 - 1.550

Quartz

Cat’s Eye

3.68 - 3.78

8.5 Mohs

1.746 - 1.755

Chrysoberyl

Chalcedony

2.65

7.0 Mohs

1.544 - 1.553

Quartz

Chlorspinel

3.58 - 4.06

8.0 Mohs

1.712 - 1.717

Spinel

Chrome Pyrope

3.50 - 4.30

6.5 - 7.5 Mohs

1.730 - 1.760

Garnet

Chrysoberyl

3.68 - 3.78

8.5 Mohs

1.746 - 1.755

Chrysoberyl

Chrysoprase

2.65

7.0 Mohs

1.530 - 1.550

Quartz

Citrine

2.65

7.0 Mohs

1.532 - 1.554

Quartz

Color-Change Garnet

3.50 - 4.30

6.5 - 7.5 Mohs

1.730 - 1.760

Garnet

Demantoid

3.50 - 4.30

6.5 - 7.5 Mohs

1.880 - 1.900

Garnet

Diamond

3.51

10 Mohs

2.417

Diamond

Dravite

3.03 - 3.25

7.0 - 7.5 Mohs

1.610-1.661

Tourmaline

Emerald

2.63 - 2.91

7.5 - 8.0 Mohs

1.560 - 1.605

Beryl

Feldspar

2.55 - 2.76

6.0 - 6.5 Mohs

1.518 - 1.572

Feldspar

Fire Opal

1.98 - 2.25

5.5 - 6.5 Mohs

1.430 - 1.460

Opal

Garnet

3.50 - 4.30

6.5 - 7.5 Mohs

1.730 - 1.760

Garnet

Ghanospinel

3.58 - 4.06

8.0 Mohs

1.712 - 1.747

Spinel

Goshenite

2.63 - 2.91

7.5 - 8.0 Mohs

1.570 - 1.600

Beryl

Green Quartz

2.65

7.0 Mohs

1.540-1.550

Quartz

Grossular

3.50 - 4.30

6.5 - 7.5 Mohs

1.880 - 1.940

Garnet

Heliodore

2.63 - 2.91

7.5 - 8.0 Mohs

1.570 - 1.600

Beryl

Heliotrope

2.65

7.0 Mohs

1.535 - 1.539

Quartz

Hessonite

3.50 - 4.30

6.5 - 7.5 Mohs

1.730 - 1.760

Garnet

Hyacinth

4.60 - 4.70

7.5 Mohs

1.777 - 1.987

Zircon

Indicolite

3.03 - 3.25

7.0 - 7.5 Mohs

1.610 - 1.640

Tourmaline

Jade

2.90 - 3.10

6.0 Mohs

1.640 - 1.667

Jade

Jadeite

3.23 - 3.43

6.5 - 7.0 Mohs

1.640 - 1.667

Jade

Jargon

4.60 - 4.70

7.5 Mohs

1.777 - 1.987

Zircon

Jasper

2.65

7.0 Mohs

1.540 - 1.550

Quartz

Labradorite

2.55 - 2.76

6.0 - 6.5 Mohs

1.560 - 1.572

Feldspar

Lapis Lazuli

2.70 - 2.90

5.0 - 5.5 Mohs

1.500 - 1.550

Lapis Lazuli

Malaia

3.50 - 4.30

6.5 - 7.5 Mohs

1.880 - 1.940

Garnet

Matura Diamond

4.60 - 4.70

7.5 Mohs

1.777 - 1.987

Zircon

Moonstone

2.55 - 2.76

6.0 - 6.5 Mohs

1.518 - 1.526

Feldspar

Morganite

2.63 - 2.91

7.5 - 8.0 Mohs

1.585 - 1.594

Beryl

Morion

2.65

7.0 Mohs

1.540 - 1.550

Quartz

Nephrite

2.90 - 3.10

6.0 Mohs

1.600 - 1.641

Jade

Onyx

2.65

7.0 Mohs

1.531 - 1.539

Quartz

Opal

1.98 - 2.25

5.5 - 6.5 Mohs

1.440 - 1.460

Opal

Orthoclase

2.55 - 2.76

6.0 - 6.5 Mohs

1.518 - 1.526

Feldspar

Peridot

3.22 - 3.45

7.0 Mohs

1.635 - 1.690

Peridot

Peristerite

2.55 - 2.76

6.0 - 6.5 Mohs

1.560 - 1.572

Feldspar

Praziolite

2.65

7.0 Mohs

1.540 - 1.550

Quartz

Pyrope

3.50 - 4.30

6.5 - 7.5 Mohs

1.730 - 1.760

Garnet

Pyrope-Almandine

3.50 - 4.30

6.5 - 7.5 Mohs

1.730 - 1.760

Garnet

Pyrope-Spessartine

3.50 - 4.30

6.5 - 7.5 Mohs

1.730 - 1.760

Garnet

Quartz

2.65

7.0 Mohs

1.544 - 1.553

Quartz

Red Beryl

2.63 - 2.91

7.5 - 8.0 Mohs

1.570 - 1.598

Beryl

Rhodolite

3.50 - 4.30

6.5 - 7.5 Mohs

1.740 - 1.770

Garnet

Rock Crystal

2.65

7.0 Mohs

2.000

Quartz

Rose Quartz

2.65

7.0 Mohs

1.540 - 1.550

Quartz

Rubellite

3.03 - 3.25

7.0 - 7.5 Mohs

1.610 - 1.640

Tourmaline

Rubicelle

3.58 - 4.06

8.0 Mohs

1.712 - 1.717

Spinel

Ruby

3.96 - 4.05

9.0 Mohs

1.757 - 1.779

Corundum

Sapphire

3.96 - 4.05

9.0 Mohs

1.757 - 1.779

Corundum

Sapphire Spinel

3.58 - 4.06

8.0 Mohs

1.712 - 1.747

Spinel

Siberite

3.03 - 3.25

7.0 - 7.5 Mohs

1.625-1.675

Tourmaline

Smoky Quartz

2.65

7.0 Mohs

1.540 - 1.550

Quartz

Spessartine

3.50 - 4.30

6.5 - 7.5 Mohs

1.790 - 1.810

Garnet

Spinel

3.58 - 4.06

8.0 Mohs

1.712 - 1.717

Spinel

Sunstone

2.55 - 2.76

6.0 - 6.5 Mohs

1.560 - 1.572

Feldspar

Topaz

3.50 - 3.60

8.0 Mohs

1.607 - 1.627

Topaz

Topazolite

3.50 - 4.30

6.5 - 7.5 Mohs

1.880 - 1.940

Garnet

Tourmaline

3.03 - 3.25

7.0 - 7.5 Mohs

1.603 - 1.655

Tourmaline

Tsavorite

3.50 - 4.30

6.5 - 7.5 Mohs

1.739 - 1.744

Garnet

Turquoise

2.60 - 2.80

5.0 - 6.0 Mohs

1.610 - 1.650

Turquoise

Uvarovite

3.50 - 4.30

6.5 - 7.5 Mohs

1.740 - 1.870

Garnet

Verdilite

3.03 - 3.25

7.0 - 7.5 Mohs

1.612-1.638

Tourmaline

Water Opal

1.98 - 2.25

5.5 - 6.5 Mohs

1.440 - 1.460

Opal

White Opal

1.98 - 2.25

5.5 - 6.5 Mohs

1.440 - 1.460

Opal

Zircon

4.60 - 4.70

7.5 Mohs

1.777 - 1.987

Zircon