Cerussite (also known as lead carbonate or white lead ore) is a mineral consisting of lead carbonate (PbCO3), and is an important ore of lead. The name is from the Latin cerussa, white lead. Cerussa nativa was mentioned by Conrad Gessner in 1565, and in 1832 F. S. Beudant applied the name céruse to the mineral, whilst the present form, cerussite, is due to W. Haidinger (1845). Miners' names in early use were lead-spar and white-lead-ore.
Cerussite
Crystals of cerussite, a secondary lead ore
At 890 carats, the Light of the Desert (located at Toronto's Royal Ontario Museum) is the world's largest faceted cerussite.
Colorless cerussite crystal that has been included by wisps of light green malachite
Ore is natural rock or sediment that contains one or more valuable minerals concentrated above background levels, typically containing metals, that can be mined, treated and sold at a profit. The grade of ore refers to the concentration of the desired material it contains. The value of the metals or minerals a rock contains must be weighed against the cost of extraction to determine whether it is of sufficiently high grade to be worth mining and is therefore considered an ore. A complex ore is one containing more than one valuable mineral.
Manganese ore – psilomelane (size: 6.7 × 5.8 × 5.1 cm)
Lead ore – galena and anglesite (size: 4.8 × 4.0 × 3.0 cm)
Granitic pegmatite composed of plagioclase and K-feldspar, large hornblende crystal present. Scale bar is 5.0 cm
Piece of kimberlite. 11.1 cm x 4.5 cm