Categories
Geology

The Mohs Hardness Scale: Comparing the hardness of minerals

Diamond is commonly known to be the hardest material, but how do other minerals compare with each other? That’s the question the Mohs hardness scale, introduced by Friedrich Mohs in 1812, aims to answer. This graphic looks at his scale and where different minerals and other substances appear on it.

Categories
Colourful Chemistry Inorganic Chemistry

What Causes the Colour of Gemstones?

There are a wide range of gemstones used in jewellery, with each having its own characteristic colour – or, in some cases, a range of colours. The origin of these colours has a chemical basis, and the precise colour┬ácan vary depending on the chemical composition of the gemstone. Interestingly, many minerals are actually colourless in […]