Volcanic glass (obsidian) with a conchoidal fracture
Keywords
obsidian,
volcanic,
glasses,
igneous,
black,
fracture,
shiny,
curved,
isolated,
natural,
physical,
semi-precious,
sharp,
gem,
esoteric,
glassy,
shape,
vitreous,
gem,
raw,
material,
resource,
geology,
lava,
volcano,
semitransparent,
geologic