Botryoidal Turkish Crater Agate with Hematite & Goethite spodumene Pyrite after pyrrhotite pseudomorph is

Pyrite after pyrrhotite pseudomorph is a mineral specimen that shows the replacement of pyrrhotite by pyrite

From the famous zeolite locality at Jalgaon District

Tenebrescence is the ability of some materials to change their color when exposed to sunlight

on a layer of chalcedony over a trimmed basalt matrix pocket

Botryoidal Turkish Crater Agate with Hematite & Goethite spodumene Pyrite after pyrrhotite pseudomorph isLustrous botryoidal crater agate cluster with hematite & goethite. Size: 95 x 55 x 45 mm. 352 grams From Cubuk, Ankara Province, Turkey Botryoidal agate is a type of agate that has a rounded, grape like appearance. It is formed when silica rich water fills cavities in rocks and deposits layers of chalcedony, a microcrystalline variety of quartz. The botryoidal shape is created by the growth of tiny spherical crystals on the surface of the chalcedony.