Metamorphic rocks with a non-foliated texture show metamorphic change that involves what

Explanation:

well I'm not 100% sure but I studied a little bit with rocks and crystals I've noticed that the hotter the temperature are it does not matter if it is Obsidian the hotter it is the more shinier it will become so the texture of it has to be a right temperature to be able to create a different texture such as a diamond and a diamond has to be compressed so hard that it will turn into diamond this is just an explanation please do not take this as a real answer I hope this help you though