Satin spar

Satin Spar is a sparkling variety of gypsum, also known as "feather gypsum", used in gemstone carvings. It is very soft but accepts a good polish. Satin spar is naturally white, pink, pale orange, or pale brown, but can be dyed to almost any solid hue. (This process kills its sparkle, however.) A typical specimen has a base value of 10gp.