Dioptasa
Dioptasa is a mineral with formula CuSiO₃·H₂O, in the Silicatos (Ciclosilicatos) group. This specimen comes from Mina Tantara, Shinkolobwe, Katanga, Congo and joined the Terrium collection in 2025.
Description
Narrow beige dolomite plate covered by a dense band of very dark green dioptase crystals, with vitreous lustre and well-defined faces.
About Dioptasa
Dioptase is a hydrated copper cyclosilicate, deep green to emerald green. It forms small but very lustrous crystals, typically in the oxidised zones of copper deposits. It has been on the rise for some years. Its main appeal lies in the contrast between colour, lustre and partial transparency.
About the locality
Mina Tantara, in Shinkolobwe, Haut-Katanga, is a small abandoned copper deposit, formerly worked as an open pit. It is a classic locality for Congolese dioptase, known for cavities with green crystals on a light matrix, sometimes associated with dolomite, plancheite and other copper minerals.
Technical data
- Catalogue No.
- 0487
- Internal reference
- T0108
- Composition
- CuSiO₃·H₂O
- Name
- Dioptasa
- Group
- Silicatos (Ciclosilicatos)
- Matrix
- Dolomita
- Mine
- Mina Tantara
- District / Municipality
- Shinkolobwe
- Province
- Katanga
- Country
- Congo
- Size (cm)
- 10 x 4 x 0.8
- Acquired
- 2025
- Etymology
- From the Greek dia ("through") and optos ("visible"). It was named by Haüy, on discovering that its internal cleavage planes could be seen simply by looking through the transparency of its crystals.
- Quality
- Buena
- Value trend
- Estable
Related specimens
- Berilo (Aguamarina) — China
- Berilo (Aguamarina) — Pakistán
- Berilo (Aguamarina) — Namibia
- Berilo (Aguamarina) — Myanmar
- Cordierita — España
- Dioptasa — Congo
- Dioptasa — Congo
- Dioptasa — Namibia