Dioptase

High-end Mineral Specimens

Dioptase is a hydrated copper cyclosilicate whose copper gives it an intense emerald- to bluish-green color. It forms transparent to translucent trigonal crystals with perfect cleavage, hardness near 5, and exceptional brilliance, but its brittleness limits the size and durability of cut gems.

Identity

Material or variety: Dioptase
Scientific or material identity: Dioptase
Classification: Natural mineral or mineral variety
Composition or formula: CuSiO₃·H₂O
Crystal system or structure: Trigonal
Geological or manufacturing origin: Can form in more than one geological environment, or combines several materials.
Mohs hardness: 5

Origins

Kazakhstan · Namibia · Republic of the Congo

Appearance & optical properties

emerald-green transparent dioptase.

History & discovery

Green crystals found by copper miners at Altyn-Tyube in present-day Kazakhstan were initially mistaken for emerald. In 1797, French mineralogist René Just Haüy recognized them as a new mineral and named it from Greek words meaning “through” and “visible,” referring to cleavage planes visible inside intact crystals.

Uses & care

Common uses: Dioptase is prized mainly as a mineral specimen. Transparent pieces are occasionally cut into small gems, and ground material has also been used as a green pigment.
Handling and cleaning: Handle it very gently because its perfect cleavage and brittleness make it easy to break. Never use an ultrasonic cleaner; avoid impacts and do not create or inhale dioptase dust.

Jewellery

5 pieces of Dioptase jewellery. Learners earn each one in DigMyGem by learning words; until then it shows as a silhouette.

Tsumeb Emerald Study
Ring
A ring set with a small cabochon of dioptase from the famous Tsumeb mine, a green so deep it rivals emerald. The stone is soft, so it is worn with care.
Copper Emerald Drop
Pendant
A pendant of one glowing dioptase crystal suspended in a delicate gold loop, its colour shifting between emerald and blue-green. It was cut to show the gem's needle-bright fire.
Verdigris Diadem
Tiara
A light gold tiara set with a row of small dioptase gems, their intense green set off by the warmth of the metal. It was made for a collector rather than a queen.
Green Spark Earrings
Earrings
An imagined pair of earrings holding tiny clusters of dioptase, the copper mineral of brighter green than emerald.
Verdant Cluster Brooch
Brooch
An imagined gold brooch built round a cluster of dioptase crystals, brighter green than emerald.