Dioptase with Secondary Mineral Association – 29mm

This 29mm specimen is a great “half-and-half” piece. It beautifully illustrates the mineral association you’ve been seeing across this batch, featuring a distinct divide between clear, blocky crystals and a more textured, mineral-coated area.

Dioptase with Secondary Mineral Association – 29mm

Locality: Republic of the Congo (DRC)

Dimensions: 29 mm x 22 mm

Visual Characteristics

This thumbnail-sized specimen is notable for its dual-texture aesthetic. One half of the cluster is dominated by sharp, robust crystals, while the other features a complex, “frosted” mineral growth.

• Crystal Habit: The right side of the specimen features large, well-defined rhombohedral crystals with a deep, “forest-emerald” color. These crystals are blocky and show strong geometric terminations.

• Secondary Growth: The left side of the piece is coated in a velvety, light-green secondary mineral (likely Malachite or Planchéite). This coating fills the interstices between the crystals, giving that half of the specimen a softer, matte appearance.

• Luster: Exhibits a high vitreous luster on the primary crystal faces, providing sharp light reflections that contrast with the satin-like finish of the mineral coating.

• Saturation: The piece shows a rich, teal-green baseline. When illuminated, the deeper crystals reveal the characteristic “neon” glow along their edges.

Technical Summary

• Mineral: Dioptase ($CuSiO_{2}(OH)_{2}$) with secondary copper mineral accents.

• Hardness: 5 (Mohs Scale).

• Crystal System: Trigonal / Rhombohedral.

• Condition: Completely natural; a solid and interesting example of mineral paragenesis (minerals forming at different stages).

Collector’s Appeal

This 29mm piece is an excellent choice for TheRockshop customers who enjoy “association pieces.” The way the lighter secondary mineral frames the dark, glassy dioptase crystals adds a layer of visual complexity that makes it look larger and more intricate than a standard solid-green cluster.

Display Suggestion

This specimen fits perfectly in a standard thumbnail display. To highlight the two different textures, use a directional light source from the right side. This will make the glassy crystal faces “pop” while casting soft shadows across the velvety secondary growth, emphasizing the three-dimensional depth of the piece.