Page 28 - Curriculum Visions Dynamic Book

Geology
Sulphur occurs as a native element in two forms, one with rhombic crystals, the other with monoclinic crystals. It is found in native form near volcanoes and hot springs.
It also appears widely as compounds, often in the form of a sulphide compounded with a metal. Galena (lead sulphide, PbS) and pyrite (iron sulphide, FeS) are common minerals.
Gypsum (calcium sulphate, CaS) and barite (barium sulphate, BaS) are found in salt-lake deposits. Sulphur also occurs in underground salt domes and in natural gas and crude oil.They are major sources of the element for industry.
 Sulphur compounds form the basis for many drugs such as this one, which is used to assist in the control of a bowel disorder.
 This sulphur deposit is around a geyser vent near Rotorua in New Zealand.The needle-like crystals that have formed show a monoclinic structure.
Biology
Sulphur is essential to life and is found
in proteins, fatty tissues, body fluids and bones. However, some sulphur gases, particularly hydrogen sulphide, can be poisonous. Sulphur dioxide is a major part of atmospheric pollution and is responsible for acid rain. Sulphur dioxide is also used as a food preservative.
Native sulphur is toxic to many bacteria and fungi, and so is widely used in medicines and as a pesticide and fungicide.
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