Several treatments can improve a ruby’s appearance. Heating is the most common and best known. Fissure filling and diffusion can also alter a ruby’s appearance.
Figure 1 groups the main treatment methods according to whether heat is involved. The three categories involving heat are described below.
1. Heating only. The ruby is heated without additives.
2. Heating with fissure healing or glass filling. Fluxes such as borax can leave residues in healed fissures. The extent of these residues can be described as minor, moderate or significant. Glass may also be used to fill fissures and is disclosed according to the treatment identified.
3. Heating with diffusion. Elements such as beryllium or chromium can diffuse into the crystal lattice during heating and modify the colour.
Rubies with no indications of heating may still have oil in their fissures. The examination distinguishes between colourless and coloured oil. The extent of colourless oil filling can be described as minor, moderate or significant.
Treatment Disclosure and Trade Terminology
Laboratories may use combinations of letters and numbers such as H, H(a), TE, TE1, TE2 and O to describe treatments. Readers need the issuing laboratory’s code definitions to interpret them. In a transaction, an incorrect interpretation can give consumers a mistaken impression of the stone’s treatment history.
ALGT reports the treatment identified in full sentences and states its extent where applicable. This approach is consistent with the World Jewellery Confederation (CIBJO) principle of using treatment codes for communication within the trade.
ALGT recommends that descriptions of rubies specify whether the stone has been heated, filled or otherwise treated. Where the evidence supports it, the description should also state the treatment method and extent and explain how the treatment may affect durability and the assessment of value.
ALGT Ruby Report Examples
The nine ALGT report examples below (Figures 2–10) show how different findings are described in words.
Figure 1 groups the main treatment methods according to whether heat is involved. The three categories involving heat are described below.
1. Heating only. The ruby is heated without additives.
2. Heating with fissure healing or glass filling. Fluxes such as borax can leave residues in healed fissures. The extent of these residues can be described as minor, moderate or significant. Glass may also be used to fill fissures and is disclosed according to the treatment identified.
3. Heating with diffusion. Elements such as beryllium or chromium can diffuse into the crystal lattice during heating and modify the colour.
Rubies with no indications of heating may still have oil in their fissures. The examination distinguishes between colourless and coloured oil. The extent of colourless oil filling can be described as minor, moderate or significant.
Treatment Disclosure and Trade Terminology
Laboratories may use combinations of letters and numbers such as H, H(a), TE, TE1, TE2 and O to describe treatments. Readers need the issuing laboratory’s code definitions to interpret them. In a transaction, an incorrect interpretation can give consumers a mistaken impression of the stone’s treatment history.
ALGT reports the treatment identified in full sentences and states its extent where applicable. This approach is consistent with the World Jewellery Confederation (CIBJO) principle of using treatment codes for communication within the trade.
ALGT recommends that descriptions of rubies specify whether the stone has been heated, filled or otherwise treated. Where the evidence supports it, the description should also state the treatment method and extent and explain how the treatment may affect durability and the assessment of value.
ALGT Ruby Report Examples
The nine ALGT report examples below (Figures 2–10) show how different findings are described in words.
Figures
Click any image to enlarge
