Obsidian is a natural volcanic glass with potentially sharp fracture edges.
Glass
cuz glass is sharp and painful!
the glass that broke will turn sharp then if you stab yourself the broken glass will stab you.
sharp glass is one
Urea is a pure crystalline compound so has a sharp melting point while glass is an amorphous mixture.
If you tap your glass bead on glass it will make a "sharp" sound. If you tap your bead on glass and it makes a "dull" sound, it is most likely not made of glass.
glass feels smooth and glass is made from sand and water =]
Just wanted to add It's a smooth crack through the glass...can't feel anything sharp on either side.
Yes. Coral has a bony skeleton that is like ceramic. If it breaks, it can be sharp like glass.
sharp enough to slice through your skin and not feel it. Just like broken glass.
Glass is a safety concern, because when glass breaks it forms pieces with extremely sharp edges that can easily cut someone.