Page 13 - Curriculum Visions Dynamic Book

Pyrite
This is the most common mineral containing sulphur. It has a brassy colour that resembles gold, and for this reason it has been called “fool’s gold”.
Some prospectors were fooled into believing they had found a rich vein of gold, when they had found a vein containing pyrite instead. It is, however, much less dense than gold, and much harder. The
darker form of pyrite is called marcasite.
Pyrite will react with oxygen in moist air so that the bright surface of a newly exposed pyrite quickly becomes dull and then changes to a
fine grey powder.
Pyrite is found abundantly in connection with hot volcanic waters on the ocean floor, but is also formed close to places where the liquids associated with volcanic eruptions
force their way into the surrounding rocks.
 Pyrite.
 A diagrammatic representation of the cubic structure of pyrite.
Iron ions Sulphur ions
cubic crystal system: groupings of crystals that look like cubes.
monoclinic system: a grouping of crystals that look like double-ended chisel blades.
pyrite: “mineral of fire”. This name comes from the fact that pyrite (iron sulphide) will give off sparks if struck with a stone.
sulphate: a compound that includes sulphur and oxygen, for example, calcium sulphate or gypsum.
 Copper sulphide ore.
 These are desert
roses, made from
calcium sulphate, or gypsum. The crystals
of this mineral look a
bit like rose petals, hence
its name. The monoclinic crystals give it a different look to the more block-like cubic crystals of pyrite.
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