Calcite (strontian-bearing) (ex Al Kidwell Collection)

Item Description

A beautiful old-time example of the seldom seen Calcites from the Minerva No. 1 Mine in Hardin County, Illinois. These specimens were originally thought to be Strontianite based upon the fact that they contained strontium, and apparently (as indicated by the accompanying label) they were thought to be pseudomorphs of Calcite after Strontianite. With that said, they are now confirmed to be strontium-bearing Calcite. This piece is loaded with attractive groups of thin prismatic scalenohedral crystals in near parallel growth, forming semi-"spray"-like aggregates of a silvery-grey hue on minor matrix. Individual crystals were hard to isolate, but I found one that measured up to 2.3 cm long. VERY little damage and quite eye-catching up close. You'll never see any more of these, as all mining in the district is closed down. This piece is easily 50+ years old, and a great representation of this unusual and hard to find material. From the worldwide mineral collection of Albert Lewis Kidwell (January 1, 1919 - August 16, 2008). Al was a well-known mineral collector and research geologist with Carter Oil Company and later Exxon Oil Company in Houston, Texas. The phosphate species Kidwellite was named in his honor in 1974.