• The Hardness Pencil:Calcite-3, Fluorite-4,Apatite-5; Orthoclase-6; Quartz-7; Topaz-8; Corundum-9, Adamas-10.
• Mohs Hardness:3-10, 8pcs in box,
• Gift box package
• Those minerals are mounted in five metal pole respectively,use the corner of those mineral to scratch the gem,you will get the hardness according to the nick you scratch,
• If there is a nick after you scratched, the sample's hardness is lower than the standard hardness pencil; If there is no nick after you scratched, that means the sample's hardness is higher than the standard hardness pencil.

Hardness pencils are pencils with a tip made of one of the 10 minerals on Mohs scale.
These pencils are used to try and scratch a stone and observe if the pencils can scratch the gem. Since this is a destructive method (it leaves a scratch)

8pcs in 1box.