Peridot
Peridot is a gemstone that was called topaz in ancient Greek and Roman times, and is known as olivine in mineralogy. It is a major component of the Earth's upper mantle, and its beautiful green color is due to trace amounts of nickel. Because it looks beautiful under night lighting, it is also called the "evening emerald."
Peridot is characterized by its beautiful yellowish-green color
Basic Information
| English Name | Peridot |
|---|---|
| Japanese Name | Kanranseki |
| Chemical Formula | (Mg,Fe2+)2[SiO4] |
| Crystal System | Orthorhombic |
| Hardness | 6.5–7 |
| Specific Gravity | 3.3 |
| Transparency | Transparent to translucent |
Characteristics and Variations
- Mantle Component: A major component of the Earth's upper mantle, found in peridotite and kimberlite.
- Birefringence: Has relatively high birefringence, resulting in a doubling effect.
- Inclusions: Small black octahedral chromite crystals are commonly observed.
- Water Lily Leaf: Patterns resembling glitter can be seen.
Origins, Aliases, Treatments, and Similar Stones
Representative Origins: St. John's Island (Red Sea, now extinct), Arizona, New Mexico, Kohistan (Pakistan), etc.
Aliases: Evening emerald, night emerald (appears beautiful under night light).
Treatment: Heat treatment (to reduce brownish tones).
Similar Stones: Green tourmaline, epidote
Note: In general, peridot is fragile and sensitive to acids, so it requires careful handling. Stones over 3ct are rare and expensive.