Opal – Overview
Intro
Opal is celebrated for play-of-colour and for the wide variety of looks available across white, black, crystal, and boulder material.
Overview
This starter entry positions opal as a phenomenon gem where pattern, brightness, body tone, and stability are central to the buying conversation.
About
This starter entry positions opal as a phenomenon gem where pattern, brightness, body tone, and stability are central to the buying conversation. Opal is presented here as a structured gemstone record ready for linked buyer guides, research posts, and media galleries.
Key Properties
| Mineral / material | Opal |
|---|---|
| Chemistry | SiO2·nH2O |
| Crystal system | Amorphous |
| Colour | White, black, crystal and many play-of-colour varieties |
| Refractive index | 1.37 – 1.52 |
| Specific gravity | 1.98 – 2.25 |
| Mohs hardness | 5.5 – 6.5 |
| Luster | Vitreous to waxy |
| Transparency | Transparent to opaque |
| Toughness | Fair |