Selenite Crystal "Coral Shelf" Cabinet Mineral Collectors dream! Gypsum Variant. Measures 6"x3"x4"weighs 1.46LB. Karat Weight: 3320 Many crystal Terminations. Most often transparent and colorless: it is named after Greek σεληνη= "the moon". if selenite crystals show translucency, opacity, and/or color, it is caused by the presence of other minerals including druse (a coating of small crystal points) druse is the crust of tiny, minute, or micro crystals that form or fuse either within or upon the surface of a rock vug, geode, or another crystal. will frequently form "ram's horns", "fishtail", "arrow/spear-head", and "swallowtail" twins. Selenite crystals can also exhibit "arrow/spear-head" as well as "duck-bill" twins. Both selenite crystals and gypsum flowers sometimes form quite densely in acicular mats or nets; and can be quite brittle and fragile. Gypsum flowers are usually attached to a matrix (can be gypsum) or base rock.

Selenite * General Category Sulfate mineral Formula (repeating unit) CaSO4·2H2O Identification Formula mass 172.17 Color Brown green, Brownish yellow, Greenish, Gray green, Gray white Crystal habit Earthy - Dull, clay-like texture with no visible crystalline affinities, (e.g. howlite). Crystal system Monoclinic (2/m) Space Group: A2/a Cleavage [010] Perfect, [100] Distinct, [011] Distinct Fracture Fibrous - Thin, elongated fractures produced by crystal forms or intersecting cleavages (e.g. asbestos). Mohs scalehardness 2 Luster Pearly Streak white Specific gravity 2.3 Optical properties Biaxial (-) 2V=58 Refractive index nα=1.519-1.521, nβ=1.522-1.523, nγ=1.529-1.53 Birefringence δ =0.0090-0.0100 Other characteristics non-radioactive, non-magnetic, Fluorescent. Found 2013 in Placitas NM: Location. 35° 18.069′ N, 106° 28.308′ W. Marker is near Placitas, New Mexico, in Sandoval County. Marker is on New Mexico Route 165 at milepost 3.6 west of Vista de Oro, on the left when traveling east. Click for map. Marker is in this post office area: Placitas NM 87043, United States of America.