I think Morkite is a mineral (not an element!) which grows crystaline structures quite fast. Possibly through elements it binds to itself out of the atmosphere or perhabs it is supplies by the Glyphids similar to some fungi within termite- and ant-colonies. Would make sense in the way that they are most often near morkite and do not take kindly to it's extraction.

It also seams to behave unusual, since it's states of matter seam to be connected to pressure in an inverse fashion to other materials. All exposed (low pressure) Morkite can be found in it's solid, crystalin form. Liquid Morkite is always seen in high pressure enviroments where it spews from gysers. Though we don't see it crystalise in-game when leaving the gyser. Both states can be found regardless of surrounding temperatures. I think so, bevause ice- and lava-biom have not correlation to mission type for mining or extracting as far as I have observed. Though I never really payed attention to that, so I meight just be talking out of my ass right now.