• The way a mineral reflects light
• METALLIC: opaque, looks like a metal such as gold, silver, iron, etc.
• NON-METALLIC: (needs to be more descriptive)
– VITREOUS or GLASSY - strong glint (shiny like glass)
– PEARLY (talc, some gypsum) - looks like mother-of-pearl
– RESINOUS - reflects light in a manner similar to syrup or tree sap ("glazed")
– EARTHY- dull, little or no reflection