Unformatted text preview: Figure 1.8 Two varieties of the mineral quartz. Rose quartz (left) and smoky quartz (right) each have a hardness of seven and fracture when broken. (Photo by E. J. Tarbuck) Figure 1,10 Hornblende. A generally green to black, rock-forming, amphibole mineral that often occurs in prismatic crystals (left) and has two directions of cleavage at 56° and 124° (right). (Photo by E. J. Tarbuck)...
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- Summer '10
- Light, 56°, 124°, E. J. Tarbuck