This is a cluster of gypsum crystals. They grow like this in mud flats where the wqater is saturated with gypsum. They are colored according to the color of the local sand/mud. The ones from Jet, Oklahoma, are a brick red in color. The last sample I saw colored like yours, was one a student brought back from a military deployment in the middle east. One of the nicknames for them is "Salty Dogs", gypsum being chemically a salt. Don't handle it any more than necessary, the ones from Jet, at least, have a tendency to fall apart when exposed just to the moisture in your skin.
From Becky Kelher - October 26, 2011 at 02:25:08