Gemology Hub | Gemstone & Mineral Identification Guides

Beryllium diffusion is a sapphire treatment, but detecting a trace of beryllium is not automatically the same as proving that treatment. The context of the result matters. This distinction is especially useful when reading claims about highly sensitive chemical tests. A natural example in SSEF research In its 2008 Facette, SSEF described a sapphire–chrysoberyl intergrowth from Madagascar. The study confirmed that low trace amounts of beryllium can occur in natural untreated sapphire. The researchers discussed its relationship with other elements and possible tiny inclusions. That finding does not mean beryllium diffusion is undetectable. It means a laboratory must distinguish natural occurrences from evidence consistent with artificial introduction. A simple present-or-absent rule loses that important detail. What a laboratory considers Sensitive chemical methods can examine very small concentrations and differences within a stone. Microscopic features and the distribution of ch...

Dye can change a gemstone’s appearance while leaving its underlying mineral identity the same. A blue quartz specimen is still quartz, but its colour may need a treatment description. Mineral identification and colour authenticity therefore answer different questions. What the historical study examined SSEF’s 2006 article summarised Pierre Lefèvre’s work on colouring substances and methods for recognising them in gems. The study compared different observations and analytical methods. Its main educational message is that reliable identification requires evidence from more than one approach. What each method contributes Magnification can help examine where colour appears in a stone. Spectroscopy studies how the material interacts with light. Chemical analysis may provide additional information in some cases. A useful conclusion comes from bringing the relevant results together. A negative result in one test is not the same as proof of untreated colour. The dye might be difficult t...

A red bead is not automatically natural-colour precious coral. Gem coral includes different animal skeleton materials, and the market also contains dyed products and imitations. Understanding the material and understanding its colour are two separate parts of identification. Different corals have different structures SSEF’s 2005 overview distinguishes calcitic precious coral, aragonitic blue coral and corals with horn-like organic skeletons. Their structures and physical properties differ. Fossilised coral may also have undergone mineral replacement, so it should not be treated as identical to recent coral. Clues to dye and resin Dye may collect in pores, fissures or other open spaces. Resin may appear as a different substance within these areas. Drill holes can sometimes expose useful clues that are hidden on a polished outer surface. These observations are clues, not a complete home test. A clean-looking surface does not prove natural colour. SSEF describes combining microscop...