Tumbled Prehnite / 20-40mm AVG - 1 KILO LOT Menu Flames a volcanic rock that contains

a volcanic rock that contains larger inclusions in a fine-grained stone

Conglomerate jasper incorporates white quartz and various gravel sands that were caught and compressed by ancient glaciers

Listing is for (500 to 750 grams)

75" in diameter

Tumbled Prehnite / 20-40mm AVG - 1 KILO LOT Menu Flames a volcanic rock that containsQuantity: 1 kilogram Average size range: 20 to 40 millimeters Prehnite is a semi brittle gemstone that most often forms as globules, stalactites, or in botryoidal growths. While not a zeolite itself, it is often found near zeolite deposits like heulandite or stilbite, and it was first found in what is now South Africa in the late 1700s.