Hematite (Fe2O3)
Primary iron ore. Steel-gray to reddish; distinctive cherry-red streak. Forms in sedimentary banded iron formations and hydrothermal veins.
Magnetite (Fe3O4)
Strongly magnetic iron oxide. Black, metallic luster. Important in igneous and metamorphic deposits; used in dense-media separation.
Cassiterite (SnO2)
Chief tin ore. High density, adamantine luster. Common in granite-related veins and alluvial placers.
Chalcopyrite (CuFeS2)
Most important copper ore. Brass-yellow, often tarnished. Occurs in porphyry copper systems and massive sulfide deposits.
Galena (PbS)
Lead ore with cubic cleavage and high specific gravity. Frequently associated with silver; common in Mississippi Valley-type deposits.
Sphalerite (ZnS)
Primary zinc ore. Resinous luster; color from yellow to black depending on iron content. Often found with galena.
Pyrite (FeS2)
“Fool’s gold.” Pale brass-yellow cubes or pyritohedra. Not an iron ore, but common gangue and a sulfur source historically.
Malachite (Cu2CO3(OH)2)
Bright green secondary copper mineral. Forms in the oxidized zones of copper deposits; also valued as an ornamental stone.
Smithsonite (ZnCO3)
Secondary zinc carbonate. Botryoidal crusts in oxidized zinc ores; historically smelted before widespread use of sphalerite.
Beryl (Be3Al2Si6O18)
Source of beryllium; gem varieties include emerald and aquamarine. Forms in pegmatites and hydrothermal veins.
Spodumene (LiAlSi2O6)
Major hard-rock lithium ore. Prismatic crystals in lithium pegmatites; critical for battery supply chains.
Native Gold (Au)
Occurs as nuggets, flakes, and vein fillings. Soft, malleable, dense; recovered from both lode and placer deposits.
How ore minerals are grouped
- Oxides — metals bonded to oxygen (hematite, magnetite, cassiterite).
- Sulfides — metals bonded to sulfur (chalcopyrite, galena, sphalerite, pyrite).
- Carbonates — often secondary minerals in weathered ore zones (malachite, smithsonite).
- Silicates — structural rock-forming minerals that can host Li, Be, and rare metals.
- Native elements — metals occurring in uncombined form (gold, copper, silver).
This page is a static educational summary for general reference. Grades, reserves, and mining practice vary by deposit.