Cerussite
Cerussite is just a really rare and the extremely gem that is beautiful is just a lead carbonate. It’s a person in the group that is aragonite of which also includes Aragonite and Witherite. A Cerussite gem can be as beautiful as being a diamond as it has very high dispersion (greater than a diamond), is usually colourless and has a lustre that is adamantine. Its high dispersion, high lustre and high thickness are because of its lead content. Just as leaded crystal glass has more brilliance and sparkle due to the lead content, so does Cerussite. Cerussite crystals are abundant but Cerussite is one of the most difficult gems to facet due to its softness (3.0-3.5), its brittleness and its heat that is high sensitivity. Therefore, faceting Cerussite is extremely difficult and time-consuming. Numerous break in the procedure. Few treasure cutters have actually enough time, persistence, ability and tender care that is loving deal with faceting Cerussite. Due to this, faceted Cerussite is one for the rarest of all gems. The high price of a faceted Cerussite is certainly caused by due to the fee of faceting, perhaps not the cost of the material that is rough.
Two of the most notable occurrences of facetable Cerussite crystals are Touissit mine, near Oujda, Morocco and Tsumeb, Namibia
| Category: | Carbonate mineral |
| Chemical Formula: | PbCO3 |
| Lead Carbonate | |
| Molecular Weight: | 267.21. gm |
| Composition: | Lead | 77.54 % | Pb | 83.53 % | PbO |
| Carbon | 4.49 % | C | 16.47 % | CO2 | |
| Oxygen | 17.96 % | O | |||
| 100.00 % | 100.00 % | = TOTAL OXIDE |
| Crystallography: | Orthorhombic – Dipyramidal |
| Crystal Habit: | Crystals, to 0.6 m, are tabular, equant to elongated, or pseudohexagonal dipyramidal, exhibiting many combinations. Also granular, pulverulent, stalactitic, as randomly intergrown prismatic aggregates, rarely fibrous, massive. |
| Twinning: | Common; as simple or cyclic contact twins, producing stellate pseudohexagonal or reticulated composites; as contact twins producing heart-shaped composites. Both laws may occur in one aggregate. |
| Cleavage: | Distinct on {110} and {021}, Poor on {010} and {012} |
| Fracture: | Conchoidal |
| Tenacity: | Very Brittle |
| Moh’s Hardness: | 3.0 – 3.5 |
| Density: | 6.53 – 6.58 (g/cm3) |
| Luminescence: | Fluorescent. May fluoresce yellow to golden-yellow or white under LW UV, also under X-rays. |
| Radioactivity: | Not Radioactive |
| Other: | Soluble in dilute HNO3 with effervescence. |
| 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: | Colorless, White, Pale Yellow, smoky to dark Gray, Blue, Green, Black with inclusions |
| Transparency: | Transparent to Translucent |
| Luster: | Adamantine, Vitreous, Resinous, Pearly, Dull, Earthy |
| Refractive Index: | 1.804 – 2.079 Biaxial ( – ) |
| Birefringence: | 0.2740 (very high) |
| Dispersion: | 0.055; Relatively Strong; r > v (greater than diamond) |
| Pleochroism: | None |
