Diorite
Rock
About it
Speckled black-and-white rock of white plagioclase and black hornblende with little or no quartz. Forms in the roots of volcanic arcs, often alongside granodiorite, and is polished as a decorative stone.
- Type
- Rock (igneous)
- Group
- Igneous (plutonic)
- Specific gravity
- 2.7–3
- Colours
- black and white speckled, grey, dark greenish grey
- Transparency
- opaque
Typical values: real specimens vary. For more, see mindat.org.