Several beds of anhydrite or gypsum occur in the Glen Rose or equivalent formations of central Texas, east Texas and southwest Arkansas. Recent work by Slaughter et. Each celestite zone is often distinctive in terms of crystal size, habit and associated minerals. As many as five celestite zones can be found in the eastern part of the study area where the Glen Rose is thicker. A white to yellowish alteration product encrusting celestite and calcite is generally strontianite.
Celestite casts preserved by calcite or limestone encrustations occur at several locations.
An accompanying map indicates the geographic distribution of known celestite occurrences in Lampasas and nearby counties. A suggested mineral paragenesis of the cavities in the Rodessa member of the Glen Rose is g1ven in an accompanying chart. Crystals elongated along the b-axis frequently occur in an uppermost celestite zone at outcrops where more than one zone is present. Along North Sims Creek and several tributaries in northwest Lampasas County and the adjacent area of southeast Mills County, these bladed crystals occur in two persistent and distinctive zones about eight to ten meters apart. Some of the crystals within the host cavities exhibit a salmon color near their points of contact with the cavity wall.