I could introduce the new unit, but I'm going to leave that to some experts...
Sources:
http://dictionary.reference.com/browse/mineral
https://upload.wikimedia.org/wikipedia/commons/c/c8/Dioptase-36918.jpg
http://www.sciencekids.co.nz/sciencefacts/earth/rocksandminerals.html
http://f.tqn.com/y/geology/1/S/g/V/granitesalinia.jpg
http://museumvictoria.com.au/pages/17094/imagegallery/1pic-43069.jpg
http://dictionary.reference.com/browse/mineral
https://upload.wikimedia.org/wikipedia/commons/c/c8/Dioptase-36918.jpg
http://www.sciencekids.co.nz/sciencefacts/earth/rocksandminerals.html
http://f.tqn.com/y/geology/1/S/g/V/granitesalinia.jpg
http://museumvictoria.com.au/pages/17094/imagegallery/1pic-43069.jpg