AMAZONITE

A silicate which is blue to green in colour due to the presence of lead impurities. The more lead in the sample the greener it appears. Pure amazonite is white. It is fairly soft (6 on the mohs scale) and is sensitive to heat.

It is a form of microcline feldspar and crystals may run into each other (a process known as twinning).

It is named after the river Amazon and occurs in igneous rocks. It may be found in Brazil, Canada, the Urals, Tanzania and Colorado, USA.

HEMATITE

Hematite is a silicate of iron which can be earthy or shiny in appearance. It is usually found in masses and is fairly soft (5-6 on the mohs scale).

It is the main industrial source of iron and is very widespread. It gets it's name from the Greek for blood (it becomes red when exposed to oxygen).

It may be found in igneous or sedimentary rocks when water which contains iron precipitates. In sedimentary rock it may be the cementing material between other minerals. It may be found in Brazil, Quebec (Canada) and along the shores of Lake Superior USA.