Emerald
Composition
Beryllium aluminium silicate (Be₃Al₂Si₆O₁₈) coloured by chromium or vanadium
Hardness · Crystal system
7.5–8 · Hexagonal
Mined in
Colombia, Zambia, Brazil, Ethiopia, Afghanistan
Almost every emerald contains internal fractures — the trade calls them jardin, "garden". A flawless emerald is more suspicious than impressive.
Traditionally linked to loyalty, growth and honest speech.
Care. Warm soapy water and nothing else. Never ultrasonic — nearly all emeralds are oil-treated to fill fractures, and ultrasound drives the oil out.
Spotting a fake. A flawless emerald should raise suspicion rather than excitement: genuine stones nearly always show internal fractures the trade calls jardin. Perfectly clean green stones are usually glass or synthetic.