Mineral Specimen #4441 Twinned Calcite with Included Polydymite
Grays Quarry, Hamilton, Hancock Co., Illinois
6.4 x 5.5 x 4.1 cm
A well formed, relatively large twinned Calcite crystal arises from of other twinned crystals. The crystals are semi transparent with some of the smaller crystals being more so. Many of the crytals, including the largest, have three faces on a side. Also, beveled edges are common. The surfaces of the crystals are fairly smooth with some growth lines and striations and have a glossy luster. Within some of the smaller crystals, near the base of the specimen, there are inclusions of black colored, needle like and fibrous Polydymite. This is a very good example of the twinned Calcite crystals for which this location is noted. The specimen stands just right without the use of a stand as depicted in the first two photos.
Flaws: There is some minor chipping on the edges of the largest crystal.
This mineral is also found in the following galleries: Minerals From the United States | Calcite | Sulfides and Sulfosalts | Rare Minerals | Minerals with Inclusions | Minerals Priced Between 50 and 99 Dollars
From the Robert Gannon collection