Dioptase Crystal Cluster

Description

An 8.5 cm cabinet specimen covered in densely intergrown, deep green Dioptase crystals with bright glassy faces.

This richly crystallised Dioptase specimen comes from the Mindouli District in the Republic of the Congo. Closely intergrown crystals cover the principal display face, creating a three-dimensional cluster with substantial cabinet presence.

The crystal faces have a vitreous lustre. Their deep green colour shifts toward brighter green at thinner edges and in areas that catch the light. Multiple viewing angles reveal the stepped growth and varied orientation of the crystals.

The crossing arrangement described above is an important part of the specimen’s silhouette. It lets the direction of individual crystals be followed through the group, with open spaces making their outlines more apparent. Intersecting crystals alone do not establish a specific twin law; here the description concerns the visible arrangement rather than a laboratory-confirmed crystallographic relationship.

Dioptase is a hydrated copper silicate, distinct from emerald despite its striking green colour. It forms in the oxidised zone of some copper deposits and is particularly appealing when its glassy crystal faces remain exposed. The combination of strong colour and clearly crystallised growth gives it a recognisable place among copper minerals.

A Dioptase group rewards attention to both the larger faces and the smaller crystals between them. Changes in viewing angle can turn a dark surface into a bright reflection without changing the mineral itself. Its crystal arrangement, distribution over the matrix and overall silhouette help distinguish one piece from another. These are the features that give a cluster its individual display character.

The recorded origin is Mindouli District, Pool Department, Republic of the Congo. Within a collection of Dioptase specimens, this locality gives the piece a geographical identity alongside its particular crystal habit and natural setting.

The specimen measures 8.5 × 5 × 4.5 cm, with a recorded weight of 177.5 g. The proportions give a useful guide to its place in a display, with the individual crystal arrangement and mineral association remaining the principal points of interest.

Condition: A natural mineral specimen.

Care: Dioptase is fragile. Handle by the solid base, avoid impacts and clean gently with a soft, dry brush.