Major Mineral Groups (Part 3)
Silicates (continued)
Pyroxene Pronounce:
• This group of complex silicates includes augite, shown below.
• Pyroxenes are identified by their dark colors, glassy luster, and good cleavage planes.
• Their hardness is 5 to 7.
• Their specific gravity is 3.15 to 3.5.
Augite (Photograph by Parvinder Sethi)
• This group of complex silicates includes hornblende, shown below.
• Amphiboles are identified by their glassy luster, dark colors, and good cleavage planes.
• Their hardness is 5 to 6.5.
• Their specific gravity is 2.9 to 3.6.
Hornblende (Photograph by Parvinder Sethi)