After this thread I bought some and tested it as a base for live sand. The grains are not smooth so it was months before it could sustain a decent critter population. That seemed to eliminate it as a good sand for deep sand beds.
Recently I tried soaking the sand in RO water for about a month prior to using it. The RO water seemed to partially dissolve the sand and that was enough to round out the edges. I tried using some and sure enough, the sand bed infauna flourished.
So, my suggestion is to soak the sand in fresh water prior to using it and it will work fine. I doubt that many people have the time nor patience to do this but that's the only way I would recommend it.
Caution - do NOT soak it in tap water. Make sure it's pure water.
I have not tested it yet but I predict that a bottle of white vinegar would cut the soaking time down considerably. If anyone wants something to do maybe you could test this theory for me.