Judging quality
Pakistani material from high in the Kohistan region gives the finest large clean crystals. Look for pure grassy green without brown; oil in fractures is a common treatment.
Olivine
Peridot
Gem olivine, one of very few gemstones that occurs in only one color. It arrives at the surface in basalt and, occasionally, inside pallasite meteorites.
Care
Sensitive to acid and thermal shock. Clean with mild soapy water only.
History & lore
Zabargad Island in the Red Sea supplied the pharaohs and later the Ottoman court; many 'emeralds' in old treasuries are peridot.
Cultural history, recorded as tradition rather than as medical or scientific claim.
Common questions about Peridot
- What is Peridot?
- Gem olivine, one of very few gemstones that occurs in only one color. It arrives at the surface in basalt and, occasionally, inside pallasite meteorites.
- How hard is Peridot and what is it made of?
- Peridot is a Olivine-family mineral with the composition (Mg,Fe)2SiO4. It crystallizes in the orthorhombic system and rates 6.5-7 on the Mohs hardness scale. It occurs in olive green, lime.
- Where does Peridot come from?
- Notable localities for Peridot include Pakistan (Kohistan), Myanmar, USA (Arizona), Egypt (Zabargad).
- How do you tell good Peridot from filler?
- Pakistani material from high in the Kohistan region gives the finest large clean crystals. Look for pure grassy green without brown; oil in fractures is a common treatment.
- How do you care for Peridot?
- Sensitive to acid and thermal shock. Clean with mild soapy water only.
See it in person
Photographs only go so far
Both rooms are open six days a week, and there is always someone happy to pull pieces out of the case so you can compare them under the light.