Hey Chris, Hard for me to tell unless you hold it up to the light, but it appears to be green obsidian...if it is it is extremely rare!! that is an absolute beauty! what a great find..green obsidian is highly prized...it comes from around the Burns-Hines area.
I keep coming back and looking at that! That is truly an incredible find! Google Burns green obsidian. probably 98% of the existing Burns green is on private land, the other 2% is nearly impossible to find....I've been hunting for it for years....haven't found apiece yet.