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Mineral Hardness

Diamond is the hardest natural material in the world. However, it’s also brittle. Scientifically speaking, hardness measures the ability…

Mineral Physical Properties

The optical properties of minerals attract our eyes and can give a specimen a unique character. However, mineral physical properties are also…

Crystal System Structure Chart

Structure Crystal axes and Angles Optic Character Refractive Indexes Optic Sign Pleochroism Examples Amorphous No orderNo axes IsotropicSingly…