|
Introduction
Color
Streak
Transparency
Luster
Hardness
Cleavage
Fracture
Specific Gravity
Crystal Form
Mineral Matters
Regional Minerals
|
Luster
Luster is the way the surface of a mineral reflects light. Luster should be observed on a cut or freshly broken, untarnished surface. There are two general types of luster -- metallic and non-metallic. The terms used to describe luster are:
- Metallic -- example: gold
- Vitreous (glassy) -- example: quartz, tourmaline
- Adamantine (brilliant) -- example: diamond
- Resinous (like resin or sap from a tree) -- example: sphalerite
- Greasy or waxy -- example: turquoise
- Pearly -- example: talc
- Silky -- example: asbestos
- Dull or earthy -- example: bauxite
|
Tourmanline has a vitreous (glassy) luster.
|
|
