#11817
Selenite, Marienglas from Sicily, 200 - 500 µ

Ordinary plaster can be found almost everywhere. Two special crystal forms make gypsum something special. Alabaster is a particularly fine crystalline form of gypsum in which no crystal structure is visible. Marienglas is a special form in which the gypsum crystals form layers in a particularly even order. As a result, it is transparent and the plates can be easily split into thinner platelets. The name Marienglas comes from the use of the Marienglasscheiben as window panes for small windows or relic containers. Plinius describes the use of Marienglas for windows as Lapis Specularis and as a scattering crystal to exploit the high refraction of light at the crystalline surfaces for special effects on surfaces. Even in the Middle Ages Marienglas was used as an additive in paints or plasters to increase the reflection. New in the range are our very cheap and available in large quantities varieties from Sicily. It can also be used to make larger spreaders, such as those used to be in the Renaissance and Baroque periods.