AAA grade Diamond Apophyllite

Diamond Apophyllite on Blue Chalcedony — AAA Grade Cluster (321g)

A premium, large-format specimen featuring well-formed apophyllite crystals sitting on a textured blue chalcedony matrix.

The apophyllite shows classic tetragonal crystal growth with sharp pyramidal (“diamond”) terminations and strong vertical striations across the prism faces — a key identifier of this mineral. The crystals are transparent to translucent, allowing light to pass through and reflect internally.

The base is a layered blue chalcedony (microcrystalline quartz) with a natural drusy surface, creating contrast between the glassy apophyllite and the fine crystalline matrix beneath.

Key Features

• Primary Minerals:

  Apophyllite – KCa₄Si₈O₂₀(F,OH)·8H₂O

  Chalcedony – SiO₂

• Crystal System:

  Apophyllite – Tetragonal

  Chalcedony – Microcrystalline (Quartz variety)

• Colour:

  Clear to white apophyllite

  Blue-grey chalcedony base

• Transparency:

  Apophyllite – Transparent to translucent

  Chalcedony – Translucent to opaque

• Lustre:

  Apophyllite – Vitreous (glass-like)

  Chalcedony – Waxy to dull

Feature Highlights

• Large, well-defined apophyllite crystal cluster

• Visible growth striations on crystal faces

• Sharp, geometric terminations

• Sparkling drusy chalcedony matrix

• Strong contrast between macro crystals and microcrystalline base

• Natural formation — no treatment or enhancement

Dimensions

• Weight: 321 grams

• Size: 8.7 cm x 6.8 cm

Geological & Scientific Notes

Apophyllite typically forms in low-temperature hydrothermal environments, often within basalt cavities. Silica-rich fluids deposit minerals layer by layer, allowing crystals to grow freely into open space — which is why pieces like this develop such sharp, complete terminations.

The chalcedony base forms from colloidal silica, creating the fine-grained structure seen here. The blue tone is caused by light scattering and trace mineral content within the microcrystalline network.

This combination represents two different silica formation styles: • Macro crystalline growth (apophyllite)

• Microcrystalline silica deposition (chalcedony)

Condition

• Excellent display condition

• Minor natural edge contacts consistent with formation

• Strong overall crystal integrity