AIGS Master Color Chart

AIGS Type:Type classifications were created to facilitate the communication of the appearance of rubies and sapphires. The type separation is not an indication of quality or origin. It is merely to denote a color appearance with a characteristic hue and tonal range. Understanding different types eliminates the need for lengthy description of color as well as the argument of the origins of the stones. Type A is not necessarily better than Type B, C, K, etc.or vice-versa as the sequence of the type has no significance. The terminology Sri Lanka-type, Australia-type, x-type sapphires; or Thai-type, Burma-type rubies may be used interchangeably of the A, B, C categories when describing stones.


Type A

  1. Primary hue is red with violetish or orangy overstones.
  2. Face corners almost always appear blackish.
  3. Usually of Thai origin.
  4. Known in Thai simply as “Ploy Daeng”

Type B

  1. Prominent hue is pink with either violet or orangy overtones.
  2. Tone almost never too dark.
  3. Color improves greatly under incandescent light.
  4. Fluoresces stronger than Type A and Type D in L.W and S.W. ultraviolet.
  5. Know as “Daeng Chompoo”.

Type C

  1. Moist prominent hue is red with strong orange overtones.
  2. Often accompanied by veil-like inclusions.
  3. Fluoresces stronger than Type A and Type D but usually weaker than Type B.
  4. Has a subdued luster due to inclusion.
  5. Stones from Bo Wean with characteristic orangy overtones usually fit in this category.
  6. Known as “Lai Thai” or “Deang Som”

Type D

  1. Primary hue is red with orangy overtones.
  2. Tends toward darker tones.
  3. Weakest fluorescence of all the different categories.
  4. Known as “Deang Dum”
  5. Usually of Thai origin.

Type E

  1. Purplish-red hue (unlike the other types).
  2. Lacks the violetish, brownish overtones of Type A.
  3. Usually of Burmese, Madagascar, Mozambique, Tanzania, Vietnam, Afghanistan or Sri Lankan Origins.
  4. Strongest fluorescence of all the different categories.
  5. Usually of Thai origin.


Type A

  1. These stones are recognizable by their “deep royal blue” (Violet-Blue).
  2. May come from Sri Lanka, Burma, or other sources.
  3. Bluer than Type D.
  4. Dark blackish color at facet corners.

Type B

  1. Denotes stones with a blue hue characteristic of “old “ Kanchanaburi ( milky and silky)
  2. Absence of blackish hues at facet corners compared to Type A.

Type C

  1. Keyword is “cornflower” but do not be misled by the term. Lighter than Type A and often
  2. Can be from Burma, Sri Lanka, or even Cambodia if lighter in tone.

Type D

  1. “Inky Blue” sapphires. Usually from Australia, Bangkacha Chantaburi or Elam Thailand, Nigeria, Lamdong Vietnam or China.
  2. Usually darker tones.
  3. Hexagonal color banding often present.
  4. Almost always show iron lines in the spectroscope.
  5. Greenish overtones often visible face up.

Type E not applicable

Type F

  1. Refers to sapphires with a predominant green hue.
  2. Keyword is “fancy” and there is no numerical color grade. Fancy colors, although extremely attractive, are usually for collectors.

Type G

  1. For all sapphires with a predominant green hue.

Type H

  1. “Sri Lanka-Type” yellow sapphires. Primary hue lacks brownish overtones.
  2. Usaully accompanied by fingerprints and feathers.
  3. Orangy fluorescence in L.W. and weak orangy fluorescence in S/W.
  4. Usaully absence of Iron lines.

Type K

  1. Category foe Thai, Australian-type yellow sapphires.
  2. Brownish overtones almost always noticeable at the facet corners.
  3. The body color is deeper and darker in appearance compared to Sri lankan stone.
  4. Cleaner and sharper luster.
  5. May have straight color banding sometimes greenish.
  6. Iron lines present in spectroscope.

Type L

  1. Refers to sapphires from Songea ( Tanzania), Madagascar, and Sri Lanka.
  2. Usually orangy-Red color with varying tones.
  3. Almost always heat-treated with Beryllium diffusion to enhance the color.

Type P

  1. Refers to sapphires from Madagascar, Tanzania, and Sri Lanka.
  2. Usually purplish-Pink to violetish-Pink in lighter tones.
  3. For all sapphires with light pastel pink hue.