All of our Minerals & Crystals are 100% Genuine Specimens & come with a Certificate of Authenticity
These are special Tumblestones that have been produced from some of the most beautiful, and sometimes hard to obtain, minerals from around the world. These specimens are sold as individual stones.
Tumblestones or “tumbled stones” as they are also referred to are made by “tumbling” rough crystals, minerals or rocks in grit for a number of days in a tumbler machine. Different grades of grit are used in the process until the rough edges are smoothed, then polish is added to bring a soft shiny surface to the specimen. Because of this process each stone will be unique in shape and colour.
Prehnite is an inosilicate of calcium and aluminium. It most often forms as stalactitic or botryoidal aggregates, with only just the crests of small crystals showing any faces, which are almost always curved or composite. Prehnite is brittle with an uneven fracture and a vitreous to pearly luster. Its hardness is 6-6.5, In April 2000, rare orange prehnite was discovered in the Kalahari Manganese Fields, South Africa. Prehnite is mostly translucent, and rarely transparent.