spherulite
Noun
Meaning
A minute spherical crystalline body having a radiated structure, observed in some vitreous volcanic rocks, as obsidian and pearlstone.
Source: Webster's dictionarySynonyms
amorphous
single crystal
nanocrystal
twin crystal
microcrystal
mesocrystal
polycrystal
fibrous crystal
polyhedral crystal
columnar crystal
dendritic crystal
granular crystal
acicular crystal