Characteristics
The following geologic characteristics define a cinder:
- Uncemented
- Vitric
- Having bubble-like cavities, called vesicles
- Measuring not less than 2.0 millimeters in at least one dimension
- Apparent specific gravity between 1.0 and 2.0
- Typical cinders are red or black in color.
- Contain numerous gas bubbles "frozen" into place as magma exploded into the air and then cooled quickly.
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