April-Diamond

Colour	Colourless (variable colour if contains impurities)
Formula	C
Group	-
Uses	Jewellery
Origins	Found in Kimberlite (see below) and in alluvial deposits
Locations	Australia, Ghana, Tanzania

Diamond is the hardest substance on earth (10 on the mohs scale) and therefore can only be scratched by other diamonds. It is the most valuable gemstone when it is in it's pure form (colourless). Less pure specimens are used for polishing and drilling.