pyrocrystalline

[ pahy-ruh-kris-tl-in, -ahyn, -een ]
/ ˌpaɪ rəˈkrɪs tl ɪn, -ˌaɪn, -ˌin /

adjective Petrography.

crystallized from a molten magma or highly heated solution.

Origin of pyrocrystalline