Ceramic 9 Aluminum Oxide
Anodized Aluminum 6.5 Electrolytic coat
Steel 5 to 8.5 .
Cast Iron 5 .
Corian 4 Methal methacrylate plastic
Copper 3 .
Zink 2.5 .
Plexiglass, Lucite 2 Acrylic Plastic
Type Metal 2 Lead, tin, antimony, copper
Pewter 2 Lead, tin and variables
Metallized Resin 1.9 Metal pelets in resin
Type Metal 1.8 Tin and variables
Tin 1.7 .
Mylar 1.6 Polyester plastic
Acetate 1.6 .
Lead 1.5 .
Polyurithane 1.5 .
Vinyl 1 .
Beeswax/carnuba 0.3 .
Beeswax 0.2 .

Note: These figures are approximate and are put together for your general reference.

The Moh’s scale is really not appropriate for metals or polymers, because it is based on what scratches what in inelastic materials.

A deformable material like metal is measured by the displacement of the metal by a diamond point or a ball, as in the Rockwell or Brinell system. Polymers are usually measured by Shore Durometer, which also measures the deflection of a point under a force.


Compliments of The International Gem Society