Gems that grew in living things: natural vs cultured pearls, dyed and reconstituted coral, amber against copal and plastic.
Shell, mother-of-pearl, bone and horn are all imitated in plastic. The layered, canalled and fibrous structures that identify each natural material.
Only an X-ray sees inside a pearl. What the radiograph shows for natural, bead-nucleated and tissue-nucleated pearls, and how nacre thickness is read.
The tooth test separates nacre from smooth coated imitations and nothing more. Why it cannot tell natural from cultured, and the better home check.
Pearl, coral, amber, jet and shell are soft and chemically sensitive. What damages them, how to clean and store them, and what a lab can say about condition.
Imitation pearls are coated glass, plastic or shell beads. The drill-hole, surface, weight and structure checks that separate them from nacre.
Pearl, coral, amber, shell and bone cannot be identified by RI alone. The structural, density, UV, X-ray and spectroscopic methods a lab uses.
Dye is the commonest treatment in red coral. The drill-hole, magnification, UV, solvent and spectroscopic checks a laboratory uses to detect it.
Basra pearls are natural Gulf pearls, now essentially unobtainable. Why the name is attached to cultured pearls and what a lab can actually confirm.
Amber is fossil resin, copal is young resin, plastic is neither. The salt-water, UV, solvent and magnification checks that separate all three.
The laboratory examines Rudraksha, gemstones, malas, bracelets and crystals and issues a numbered, PIN-protected report you can verify online at any time.