Stilbite & Apophyllite - Poona, India | Ref. 571

This piece features a combination of stilbite and apophyllite from Poona, India, collected in 2023. The stilbite forms the main structure, showing warm tones ranging from beige to light orange with clearly defined volumes.

Across the surface, the stilbite develops a relief made up of needle-shaped, sharp crystals arranged tightly together, giving the piece a very textured appearance. In contrast, the apophyllite appears as clearer crystals—translucent to slightly greenish depending on the angle—resting on the stilbite. Some crystals stand alone, while others form small grouped clusters, creating several focal points on the specimen.

The piece measures approximately 62 mm in width and 38 mm in height.

🟢 Mineral Information

- Stilbite – Chemical formula: NaCa₂Al₅Si₁₃O₃₆ · 14 H₂O

- Stilbite – Crystal system: Monoclinic

- Stilbite – Lustre: Vitreous to pearly

- Stilbite – Hardness: 3.5–4 (Mohs)

- Stilbite – Density: Approx. 2.1–2.2 g/cm³

- Apophyllite – Chemical formula (group): KCa₄Si₈O₂₀F · 8 H₂O (apophyllite-K_F)

- Apophyllite – Crystal system: Tetragonal

- Apophyllite – Lustre: Vitreous to pearly

- Apophyllite – Hardness: 4.5–5 (Mohs)

- Apophyllite – Density: Approx. 2.3–2.4 g/cm³