Ulexite mineral specimens from California, USA. A mineral similar to gypsum, ulexite is able to transmit light through its long axis, meaning if placed above an image or text, will transmit it to the samples surface as an image. Hence the name TV rock, excellent for children, these pieces are available in several sizes and will come supplied in a card tray with an information label.
Ulexite is an evaporite mineral which forms due to the evaporation of water leaving behind minerals in a certain location, similar to gypsum. Named after the German chemist Georg Ludwig Ulex (1811–1883) who first discovered the mineral, it forms with a silky white fibrous crystal habit which has the ability to transmit light along the longest axis.This gives ulexite the unique ability to transmit images through its self when viewed from above its longest axis, giving the appearance that what ever text or image you hold the specimen over, is contained within the mineral, similar to old CRT televisions. This ability makes the mineral attractive to young children as it gives then something more than to just look at, but to investigate its properties, hence its nickname of 'tv rock'. These samples, although mostly clear, will contain some impurities, but does not detract from viewing it. They come from California, USA and are available in several sizes, supplied in a card tray with an information label.