Other

Monazite Group

Nacre

Hardness: 2.5 - 4.5

Nadorite Group

Natrotantite Group

Gem

Nephrite

Hardness: 6.0 - 6.5

Neptunite Group

Nickeline Group

Non-stoichiometric Perovskites Group

Nordite Group

Northupite Group

Nunderite

Hardness: 6.5 - 7.5

Nzuri Moyo

Hardness: 6 - 7

Obsidian

Hardness: 5 - 5.5

Olivenite Group

Olivine Group

Oolitic Limestone

Hardness: 3-4

Opalized Ammonite

Hardness: 5.5 - 6.5

Orbicular Granite

Hardness: 6-7

Orgone Stone

Orthopinakiolite Group

Osbornite Group

Osumilite Group

Oxyspinel Group

Palermoite Group

Pallasite Meteorite

Palygorskite Group

Parisite Group

Pascoite Family Group

Pavonite Homologous Series Group

Pearceite-polybasite Group

Pearl

Hardness: 2.5 - 4.5

Pebble

Pentlandite Group

Perhamite Group

Periclase Group

Perovskite Supergroup

Petrified Wood

Hardness: 7

Pharmacosiderite Supergroup

Phenakite Group

Phosphoferrite Group

Phosphuranylite Group

Picromerite Group

Pinakiolite Group

Pink Sapphire

Hardness: 9

Plagionite Group

Plastic

Hardness: Variable

Porcelain

Hardness: 6-7

Preisingerite Group

Proustite Group

Pruskite

Hardness: 1.5 - 2

Puddingstone

Hardness: 6.5-7

Pumpellyite Group

Pyrite

Hardness: 6 - 6.5

Pyrite Group

Pyrochlore Supergroup

Gem

Pyrope

Hardness: 7 - 7.5

Pyrophyllite-talc Group

Pyrosmalite Group

Pyroxene Group

Pyrrhotite Group