Look at the reply I got from Old Castle Products:
The play sand from the Caribbean was called "Tropical Play Sand". It is a natural sand called Aragonite which is only found in the Caribbean. However, the supply of this material played out and we therefore no longer offer it as a product. We do offer other natural sands in Home Depot and Lowes. They carry both silica play sand and limestone play sand. The limestone play sand is generally white. Both are suitable for sand boxes. The limestone play sand is softer and may leave a white dust residue on the children hands and clothes. This material is calcium carbonate similiar to Aragonite in chemical make up.
Thanks for your business and inquiry.
Matt Graves
COO, Oldcastle Stone Products
Would the Limestone sand be ok in a tank? And has any check out
a lowes for sand? Also, wouldn't vinegar make the limestone sand fizz, like aragonite sand?
Rev