Identifying Ores by Name and Composition
This cluster is a working vocabulary list: matching common ore names to the metal they supply and to their chemical formula, a foundational recall skill this whole chapter builds on.
Chemistry questions first require the material, particles or reaction condition to be identified before a formula or rule is selected.
Tungsten ores: scheelite and wolframite both carry tungstate
Scheelite (CaWO₄) contains the tungstate ion, WO4²-, paired with calcium. Wolframite ((Fe,Mn)WO₄, a mixed iron-manganese tungstate) is the other major tungsten ore, also built around the same tungstate ion, just paired with iron/manganese instead of calcium. Limonite (an iron oxide-hydroxide), dolomite (a calcium-magnesium carbonate) and siderite (iron carbonate, FeCO₃) do not contain tungstate at all — they are unrelated ores of iron or simple carbonate minerals.
Recognising a sulfide ore versus a carbonate or oxide ore
Copper pyrites (CuFeS₂, chalcopyrite) is a genuine sulfide ore. Malachite (CuCO₃.Cu(OH)₂) is a basic carbonate, not a sulfide. Haematite (Fe₂O₃) is an oxide ore of iron. Magnesite (MgCO₃) is a carbonate ore of magnesium. Recognising the anion type in a mineral formula — sulfide (S²⁻ or a metal-sulfur combination), oxide (O₂⁻), carbonate (CO3²-), or hydroxide (OH⁻) — is the quickest way to classify any ore by type, which in turn predicts whether it needs roasting (sulfides) or calcination (carbonates/hydroxides) as its pretreatment step.
A short list of other named ores worth knowing by formula
Cassiterite (SnO₂) is the principal ore of tin — an oxide ore, consistent with tin needing only straightforward carbon reduction after concentration, unlike more reactive metals. Pyrolusite (MnO₂) is an oxide ore of manganese, not a sulfide, carbide, or non-ore mineral. For the copper/zinc ore-matching family specifically: copper pyrites is CuFeS₂ (a sulfide), malachite is CuCO₃.Cu(OH)₂ (a basic carbonate), calamine is ZnCO₃ (a carbonate), and sphalerite (also called zinc blende) is ZnS (a sulfide) — two metals, each represented by one sulfide ore and one carbonate ore, is a useful pattern to recognise across Cu and Zn.
OlympIQ exam lens
- ✓Scheelite (CaWO₄) and wolframite ((Fe,Mn)WO₄) both contain the tungstate ion — the two major tungsten ores
- ✓Copper pyrites (CuFeS₂) is a sulfide ore; malachite (basic copper carbonate), haematite (Fe₂O₃, oxide) and magnesite (MgCO₃, carbonate) are not sulfides
- ✓Cassiterite (SnO₂, tin) and pyrolusite (MnO₂, manganese) are both oxide ores
- ✓Copper and zinc each have one classic sulfide ore (copper pyrites CuFeS₂; sphalerite/zinc blende ZnS) and one classic carbonate ore (malachite; calamine ZnCO₃)
Do not assume every common copper or zinc ore is a sulfide just because the most industrially important ones (copper pyrites, sphalerite) are. Malachite (copper) and calamine (zinc) are carbonate ores of the same two metals, requiring calcination rather than roasting as their pretreatment.
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