Rock IdentifierLapis Lazuli
Key takeaways
- Lapis is a rock, not a single mineral — mostly lazurite with calcite and pyrite.
- Golden pyrite flecks and white calcite streaks are natural, telltale features.
- Dyed howlite/jasper and dyed 'denim' lapis are common substitutes.
A blue rock with history
Lapis lazuli is a rock composed mainly of the deep-blue mineral lazurite, mixed with white calcite and glittering flecks of pyrite. Prized for over 6,000 years, it was ground into the priceless 'ultramarine' pigment of Renaissance painters. The finest comes from Afghanistan and shows an intense, even blue.
How to recognize it
Look for a rich royal blue studded with tiny gold-colored pyrite specks and, often, streaks or patches of white calcite. That combination — blue body, gold flecks, white veins — is highly characteristic. It's opaque, moderately soft (5–5.5), and feels dense. Uniform blue with no pyrite or calcite at all is actually a reason for suspicion.
Imitations & treatments
Common fakes include dyed howlite or jasper, dyed 'Swiss lapis' (really dyed jasper), and reconstituted lapis powder in resin. Dye can rub off onto a cotton swab dipped in acetone, and painted-on 'pyrite' looks too regular. Lower grades are sometimes dyed to deepen a pale, greyish 'denim' blue. Genuine lapis shows natural, irregular pyrite and calcite rather than perfectly placed specks.
