Quartz samples
Quartz is the most abundant mineral on earth's surface and can be found in a variety of colours like samples A, B and C. Quartz is a silicate mineral and is usually clear or white. Its diagnostic properties are that it shows no cleavage but breaks with conchoidal fractures and has a hardness of 7. Sample A is milky quartz and is more common than rose quartz and amethyst. Sample B is rose quartz and is distinguished by its pink colour that is caused by impurities of titanium, iron or manganese. Amethyst like sample C has a purple colour due to trace amounts of iron being naturally irradiated. Colourful samples of quartz are used as gemstones and some believe them to have healing capabilities. Sedimentary, igneous, and metamorphic rocks have all been found to contain quartz, as it forms at all temperatures. Quartz is a primary mineral in beach, river and desert sands and is commonly used in glassmaking.