AMETHYST

Amethyst is a semi precious stone and is a form of quartz (SiO2). It has the same chemical composition and physical properties apart from colour. It is purple/violet due to the presence of iron oxides and may be heated in order to enhance it's colour. (The deeper the colour the more valuable it is) However, if it is heated to very high temperatures it turns into citrine.

It gets it's name from the Greek word amethistos which means "that which pushes away drunkenness". It was considered to be a hangover remedy. It is mostly used for ornaments and jewellery.

It is mainly found in volcanic rocks and sometimes in geodes, which are cavities created by weathering.

It can be found in Australia, Brazil, India, Sri Lanka and Russia.

APATITE

A phosphate of calcium which also contains chlorine, flourine, hydrogen, oxygen and maybe some impurities. It can be a variety of colours but is usually green. It is a major source of phosphorus.

It is very soft (5 on the mohs scale) and for this reason is more widely used in industry than for jewellery. It is particularly used for making fertilizers.

It's name is derived from the Greek word apate which means deceit.

It is easily confused with other gemstones such as beryl, olivene and quartz and it is this which resulted in it being named apatite. It is derived from the Greek word apate, which means deceit. It is however identifiable because it is softer than many other gemstones.

It may be found in a variety of rocks and in locations such as Ontario (Canada), Mexico and Spain.