Meteorites View all facts Glossary Help| Meteorites View all facts Glossary Help |
| rock > aphanitic rock |
  | ||||||
| aphanitic rock comparison table | ||||||
| Subject | has texture | has composition | has crystalinity | has grain size | has solidification mechanism | has solidification timescale |
|---|---|---|---|---|---|---|
| cryptocrystalline rock | ||||||
| fine-grained rock | 0.1 to 0.3 mm | |||||
| microcrystaline rock | 0.01 to 0.1 mm | |||||
| obsidian | glass | silicates (with very few exceptions) | 0 % | too small to see with unaided eye or low power lens | extrusion onto the surface of the planet or asteroid via a volcanic eruption | very rapid |
Next rock: glass Up: rock Previous rock: amygdaloidal rock