Phonolite
Rock
Also called Clinkstone
About it
Fine-grained volcanic rock rich in feldspar and nepheline with no quartz; thin slabs ring when struck, hence its Greek name, sounding stone. Devils Tower in Wyoming is phonolite porphyry.
- Type
- Rock (igneous)
- Group
- Igneous (volcanic)
- Specific gravity
- 2.45–2.7
- Lustre
- dull
- Colours
- grey, greenish grey, tan, dark green
- Transparency
- opaque
Typical values: real specimens vary. For more, see mindat.org.