cristal d'apophyllite
Poona
Indie
4 x 3,5 x 2,4 cm
25 grammes
oude verzameling

Apophyllite crystals from Poona (now Pune), India, are world-famous mineral specimens prized for their brilliant glassy luster, high transparency, and stunning association with zeolites like peach-colored stilbite.
Origin and Geology

• Location: Found in the Pune district of Maharashtra, India, within the vast basalt cavities of the Deccan Traps lava formations.
• Formation: Formed via low-temperature hydrothermal processes, often growing alongside other secondary minerals like stilbite, scolecite, and calcite.
• Name Origin: Derived from the Greek words apo ("away from") and phylos ("leaf") because the mineral tends to flake or exfoliate when heated due to its water content.

Key Characteristics

• Color: Ranging from clear/colorless and milky white to highly sought-after mint or deep emerald green (colored by trace iron or vanadium).
• Luster: Distinctly vitreous (glassy) on crystal faces and pearly on cleavage planes.
• Crystal System: Tetragonal, frequently forming sharp pyramidal or pseudo-cubic structures.
• Hardness: Measures 4.5 to 5 on the Mohs scale, making the clusters quite fragile and sensitive to sudden temperature changes or pressure.