Minerals and Rocks

Mineral

Topaz

Topaz is a mineral made of aluminium and fluorine. It has mostly a prism shape. Pure topaz is colorless, but orange topaz is the birthstone for November (possibly the greatest month of the year). More information.

Rocks

Granite

Granite is na igneous rock made of the minerals quartz, feldspar and hornblende. It has a granular and crystalline texture. They vary in color from pink to gray. It is usually very large in size, and is very hard and tough. More information.

Gneiss

Gneiss is a metamorphic rock. Gneiss is usually rough. There are three types of gneiss rock: Lewisian, Augen Gneiss and Archean and Proterozoic Gneiss. More information.

Limestone

Limestone is a sedimentary rock composed usually of calcite and aragonite. Many limestone rocks contain skeletal fragments and marine organisms. More information.