Ulexite Ulexite forms in a block of transparent fibres and exhibits a triclinic structure and has a hardness of 2.5 on the Mohs scale of...

Tekkite These rocks are a natural glass that was formed from the impact of a meteor melting the local rock and producing a variety of...

Sapphire Sapphire is a form of Corrundum, which exhibits a trigonal structure and has a hardness of 9 on the Mohs scale of hardness....

Quartz Quartz is the purest form of SiO2, which exhibits a Trigonal structure and has a hardness of 7 on the Mohs hardness scale. Quatz...

Obsidian Obsidian is a form of volcanic glass which is released from volcanic activity. It forms no crystalline structure as it cools...

Magnetite Magnetite is metallic crystal that exhibits an isometric structure which has a hardness of 5.5-6.5 on the Moh’s hardness scale....

Kunsite Kunsite is a form of spodumene that exhibits a monoclinic structure and has a hardness of 6.5 to 7 on the Mohs hardness scale....

Iolite See Cordierite. Iceland Spar Iceland Spar is a form of Calcite, specifically Optical calcite,which was originally named after it...

Galena Galena is a form of Lead sulphide which forms in cubes and has a hardness of 2.5. It is very dense and exhibits a colour range...

Emerald Emerald is a form of beryl that forms in striking greens varying from pale to vibrant deeps. This crystal exhibits a hexagonal...