Rough Prehnite Mineral from South Africa
Rough prehnite mineral with a dusting of epidote crystals visible primarily on one side of the stone. Although mined in South Africa, prehnite can also be found in many other countries around the world.
On Mohs scale of mineral hardness prehnite grades 6 to 6½ so it's hard but also brittle. Although translucent to transparent, just like rose quartz it tends to be cloudy when faceted hence when used as a gemstone it tends to be cut as a cabochon.
Prehnite was first documented in 1788 following its discovery in Eastern Cape Province, South Africa. It was named after Colonel Hendrik Von Prehn (1733–1785) a Dutch military commander by whom it was found.
Weight (grams) : 740
Size (cms) : 11.6 x 8.9 x 9.9