I cleaned the tank and moved some things around. Well two fish that shall remain nameless were unhappy with my design and south to fix it! Sassy girls!!
Yeah I know I was worried too. The LFS swore and said it would be fine. They are a very very high quality store so I do trust them. I did run my finger along all the edges and none were of concern. It is actually not Obsidian it is a hunk of glass. Like the glass they blow into cool shapes and stuff.