These plates help you determine the hardness of unknown minerals in the field.

• Plates Determine How Hard Minerals Are
• System Uses Mohs' Scale
• Ideal for Unknown Minerals in the Field
• Custom-Swiped Edges Reduce Risk of Injury
• Simple-to-Use

Scratch your mineral across the plate determine how hard it is. If the mineral scratches the plates, it’s harder than five on the Mohs’ hardness scale.

The custom-swiped edges reduce risk of accidental injury when handling.