| DESCRIPTION: | No. 75733
|
| Mineral: | Sphalerite (Spinel Law twinned crystals)
|
| Locality: | France Stone Co. Quarry, 4.8 km east of Logansport, Cass County, Indiana |
| Description: | Superb cluster of large lustrous dark sphalerite crystals that exhibit yellow translucency under strong illumination. The sphalerite crystals are repeatedly twinned on the octahedral {111} plane following the Spinel Law of isometric twinning. From my personal collection; ex. Steve Chamberlain collection #2716; originally acquired in 1980 from George Robinson (1946-2024). See: Indiana Minerals, A Locality Index in Rocks and Minerals v.61 #3 |
| Overall Size: | 5.5x5x4 cm |
| Crystals: | 3-25 mm |
| Archived: | For reference only |
