Crystals
Crystals are formed in igneous rocks when the rocks are still in lava form. When the lava melts slowly, crystals are formed in the rock. When the rock melts fast, no crystals are formed. The size of the crystals depends on how fast or slow the lava cools. When it melts slower: larger crystals. When it melts slow: smaller/ no crystals. Examples of these crystals are in granite. Examples of no crystals is obsidian.
<-- Granite an example of an igneous rock that has crystals embedded into it.
<-- Granite an example of an igneous rock that has crystals embedded into it.