|Rare Selenite with Boulangerite from Transylvania, Romania
|Boulangerite is one of a few sulfide minerals that form fine acicular crystals that appear as hair-like fibers. The fibrous
aggregates may be so thick as to cover a specimen with hair-like fibers or it may be sparsely disseminated between other
minerals and may be confused with actual hairs or dark lint. Jamesonite and millerite are two other sulfides that form
similar acicular crystals and can be mistaken for Boulangerite. However, millerite is yellow and Jamesonite has brittle
crystals. Boulangerite is a sulfosalt, a segment of sulfides where the antimony acts more like a metal than a non-metal and
occupies a position where it is bonded to sulfurs. Boulangerite and Jamesonite have been called feather ores. A variety of
Boulangerite is called "plumosite" due to its plumose (feathery) habit and was thought to be a different mineral.
• Color is blue lead gray to gray.
• Luster is either metallic or silky.
• Transparency: Crystals are opaque.
• Crystal Habits dense or sparse felted masses of acicular crystals. Also in fibrous and compact plumose masses.
• Cleavage is good in one direction parallel to the length.
• Fracture is uneven.
• Hardness is 2.5
• Specific Gravity is 5.8 - 6.2 (heavier than average for metallic minerals)
• Streak is gray to brown.
|Unique 3 piece set with 2 layered selenite shards and one "flower" shaped piece
specimens measure; 80 x 10 x 14mm, 68 x 9 x 17mm, and the "flower" is 12-14mm diameter with 18mm stem
weight for set is 22g