Phosgenite

Phosgenite is a very rare gem that is very soft and fluoresces yellow under long wave UV light. The chemical formula of Phosgenite is Pb2(CO)3Cl2 and its molecular weight is 545.31 gm. Phosgenite has a specific gravity of  6.12 – 6.15 (g/cm3) and the refractive index of 2.118 – 2.145 Uniaxial ( + ). It is very attractive in several colors and has a high refractive index. Facetable crystals are only found in a couple locations; Sardinia, Italy and Tsumeb, Namibia.


 

Category: Carbonate minerals
Chemical Formula: Pb2(CO)3Cl2
Molecular Weight: 545.31 gm
Crystallography: Tetragonal – Ditetragonal Dipyramidal
Crystal Habit: Crystals are short prismatic; rarely thick tabular; commonly terminated to 30 cm; granular, massive.
Twinning: None

 

Cleavage: [110] Good, [001] Good, [010] Indistinct
Fracture: Conchoidal
Tenacity: Sectile, Flexible – Curved shavings or scrapings
Moh’s Hardness: 2.0 – 3.0 (varying direction)
Density: 6.12 – 6.15 (g/cm3)
Luminescence: Weakly Fluorescent; may fluoresce Yellow under LW & SW UV, X-rays and cathode rays
Radioactivity: Not Radioactive
Other: Decomposes slowly in cold water, which extracts lead chloride.
Health Warning: CAUTION: Contains Lead. Wash hands after handling. Do not lick or ingest; do not inhale dust when breaking. Do not grind dry.

 

Color: Pale yellow to yellowish brown, pale brown, smoky brown, smoky violet; colorless, pale rose, grey, yellowish grey, pale green
Transparency: Transparent to Translucent
Luster: Adamantine
Refractive Index: 2.118 – 2.145  Uniaxial ( + )
Birefringence: 0.0270
Dispersion: None
Pleochroism: Very weakly pleochroic; O = reddish pink and E = pale green in thick sections