Volcanic basalt with barnacle encrustations — igneous Identification & Properties | Geo-Gem
Volcanic basalt with barnacle encrustations is a igneous. Perform a scratch test against glass or a steel knife—basalt should scratch glass (hardness >5.5) but not be easily scratched by steel. Examine the interior with a hand lens for fine-grained, interlocking crystals vs. granular sand grains.…