AAA Apophyllite on Blue Chalcedony with Stilbite — Large Display Piece

AAA Apophyllite on Blue Chalcedony with Stilbite — Large Display Piece

A high-impact, large-scale specimen featuring well-formed Apophyllite crystals across a rich blue-grey Chalcedony matrix, with multiple peach-toned Stilbite formations embedded throughout.

This piece shows a dense crystal field with layered growth, where different minerals formed in stages, creating strong contrast between sharp glassy faces, soft fibrous textures, and natural mineral zoning.

🔬 Key Features

• AAA grade apophyllite with bright lustre and defined terminations

• Heavy crystal coverage — dense, multi-directional growth

• Blue chalcedony base adding depth and darker contrast tones

• Multiple stilbite clusters with soft peach colouring

• Visible secondary mineralisation and druzy textures

• Large, weighty piece with strong display presence

📏 Dimensions

• Weight: 360 grams

• Size: 10 cm x 8 cm

🌍 Geological & Scientific Notes

• Apophyllite forms in volcanic cavities where mineral-rich fluids crystallise during cooling

• Chalcedony develops from silica gels that solidify into microcrystalline quartz (SiO₂)

• Stilbite is a zeolite mineral forming in low-temperature hydrothermal conditions

This specimen represents a multi-stage formation environment, where:

Chalcedony formed first as a base layer

Apophyllite crystallised within open cavities

Stilbite formed later as fluid chemistry changed

This sequence creates the layered, clustered growth structure seen throughout the piece.

🧪 Mineral Information

Apophyllite

• Chemical Formula: KCa₄Si₈O₂₀(F,OH)·8H₂O

• Mohs Hardness: 4.5 – 5

• Lustre: Vitreous (glassy)

• Transparency: Transparent to translucent

Chalcedony

• Chemical Formula: SiO₂

• Mohs Hardness: 6.5 – 7

• Lustre: Waxy to vitreous

Stilbite

• Chemical Formula: NaCa₄Al₉Si₂₇O₇₂·28H₂O

• Mohs Hardness: 3.5 – 4

• Lustre: Pearly to vitreous

⚠️ Care & Handling

• Fragile crystal terminations — handle carefully

• Avoid water exposure (zeolite minerals can degrade)

• Keep out of prolonged direct sunlight

• Store separately from harder minerals

💎 Why This Piece Stands Out

This is a larger, heavier collector piece with:

• Dense apophyllite coverage

• Strong contrast between clear crystals and dark chalcedony

• Multiple stilbite formations adding natural colour variation

• Clear evidence of multi-phase mineral growth

The size + structure combination makes this ideal as a statement display specimen, not just a small cabinet piece.