Alabaster is a fine-grained massive form of gypsum. Alabaster ranges from white to yellow, pink, and brown. Due to its porosity it is often dyed. It has been used for centuries for statues, carvings, and other ornamental purposes. Treated alabaster is used as a marble simulant. Due to its extreme softness, it is ideal for fashioning into works of art.
Alabaster Characteristic Physical properties
Satin spar is an adjective used when the fibrous habit of a mineral gives it a satin luster. The term satin spar has been used in the past to describe calcite and aragonite; however, it is currently accepted as one variety of the mineral gypsum, along with selenite and alabaster.
Satin Spar Classification
||Satin Spar |
Satin Spar Optical Properties
||SWUV: Inert to weak brownish to greenish white |
LWUV: Inert to weak brownish to greenish white
Satin Spar Characteristic Physical properties
||Satin spar is a white to cream fibrous gypsum with chatoyant effect. |
When gypsum forms in rose like patterns it is called a desert rose. They are found in desert regions where liquid containing gypsum evaporates leaving the gypsum to crystallize. Gypsum roses can be distinguished from barite roses by their sharp edges. Desert roses from Chihuahua, Mexico have distinctive white edges.
Desert Rose Classification
||Desert Rose |
Desert Rose Characteristic Physical properties
Selenite is the name for transparent, colorless to near colorless crystals of gypsum, a hydrous calcium sulfate that is found in a number of forms. The name "selenite" comes from the Greek word selene, meaning "moon", no doubt in reference to the gem's white glow. Gypsum, in all varieties, is very soft and has perfect cleavage so it should be handled with care.
Selenite Characteristic Physical properties