Bought some rock today.....need ID
 

Bought some rocks today labelled as Driftstone, dunno what kind of rock it is. I google the term and get nothing.

I ran an acid test on it today,
Vinegar no bubbles, 3 mol HCL.....fizzing......

Is it moderately aquarium safe?

http://i.imgur.com/pNUW8S3.jpg
http://i.imgur.com/uflorqH.jpg
http://i.imgur.com/dRofdLB.jpg

Looks kind of like petrified wood to me.

Petrified Wood +1

the way it's weathered looks somewhat like limestone (which also fits with the acid test) possibly some sort of marble? it looks like it's been recrystalized, so maybe some sort of low-grade metamorphism. It's been a while since I've done any geologing, so...

Odds are it will raise pH and hardness, may not be an issue for you, especially if your tap water is already hard.

That is not petrified wood at all. It's a limestone of some sort, reaction to HCL and the weathering gives it away. It will alter your water parameters, but should be safe for your inhabitants. Keep in mind if you bleach it, it will turn bone white. That may or may not be your goal, but keep in mind when preparing it for your aquarium.