Smithsonite
| Colour | Blue, Green, Pink, White, Gray, Yellow |
|---|---|
| Mohs hardness | 4.5 |
| Lustre | Vitreous, may be pearly |
| Streak | White |
| Crystal system | Trigonal |
| Transparency | Translucent |
| Cleavage | Perfect on [1011] |
| Fracture | Uneven, sub-conchoidal |
| Chemical formula | ZnCO 3 |
| Specific gravity | 4.4–4.5 |
What is Smithsonite?
Smithsonite, also known as zinc spar, is the mineral form of zinc carbonate (ZnCO3). Historically, smithsonite was identified with hemimorphite before it was realized that they were two different minerals. The two minerals are very similar in appearance and the term calamine has been used for both, leading to some confusion. The distinct mineral smithsonite was named in 1832 by François Sulpice Beudant in honor of English scientist James Smithson (c. 1765–1829), who first identified the mineral in 1802.
How to identify Smithsonite
- Lustre: Vitreous, may be pearly.
- Hardness: Mohs 4.5 — soft; a knife will scratch it.
- Streak: White.
- Habit: Trigonal crystal system.
Smithsonite in different forms
Stones often confused with Smithsonite
Frequently asked questions
How hard is Smithsonite?
Smithsonite is Mohs 4.5 on the hardness scale.
What colour is Smithsonite?
Smithsonite is typically blue, green, pink, white, gray, yellow (White, grey, yellow, green to apple-green, blue, pink, purple, bluish grey, and brown).