Metallic--looks like a metal (i.e., shiny and opaque)

Submetallic--duller, less reflective than metallic

Nonmetallic - Adamant--hard, sparkly diamond look

Nonmetallic - Resinous--similar to amber, not quite glassy

Nonmetallic - Vitreous/Glassy--similar appearance to glass

Nonmetallic - Pearly--slight mother-of-pearl appearance on cleavage face

Nonmetallic - Greasy--looks oil-coated

Nonmetallic - Silky--fine, parallel fiber look

Nonmetallic - Dull--plain or clay/soil-like appearance