WOW, great info. I was just looking at "Calcium carbonate" and if crushed lime stone was the same, or so close in % it could be used. I personally hate a company buying a ton of something at $30 and selling it at $5 a pound. Plus I live near a huge rock/cement/stone supplier.
I am 45 and retired, and helping at the reptile shop I worked at as a kid. We hate sand. But I got a few beardies I want to breed and everyone uses sand. So I research heavily. To the point at times I get to much info. We had the vets for Cleveland Zoo do surgery on a leopard geco from impaction. I thin from calcisand? Please do not hold me to that. But it was suppose to be one of those safe sands.
My thining is the larger the lizard the easy or better chance to pass fine sand. I never once thought of the sand (which can be a term of particle size) be so fine, it lines the gut. I personally use aspen for larger stuff, but would love to have a more decorative substrate, and I'm cheap or wise? I research where teh small bags are made and buy in bulk. I can get crushed limestone for $30 a ton. At different grades too. I can not fine %'s on "Calcium carbonate" in limesteone, but it appears to be extremely large. Hence the same as the commercial product, I presume?
Well, back to researching stuff. anyone with great ideas on subtrates that look good and are safe, I'd love to here them.
I do not post much here, do not want to break rules, I see links for urls and images. I feel safe on the image. With a bad back, I'm always on IM, guess my ID lol
Side note, I use to love to build almost anything, including my log home. I get on a topic and really dig into fact on quality of items and prices. I hate being screwed on material prices.
thanks
Mettzilla
I just saw I was looking at an archive from a search from google, so here is the original post:
... in a local petstore today, and the label expressly said in the upper right hand corner - "*quartz* sand - much better for reptiles than silica sand" - which makes no sense - quartz sand and silica sand are the same thing. But it didn't say anything about calcium carbonate. Meanwhile the bag next to it - a much coarser sand, was the T-Rex "Bone-Aid Calcisand" stuff which did state that it was calcium carbonate.
The test would be to get samples of both, and add a few drops of hydrochloric acid to the samples. (This is a standard test in geology labs to determine the calcium carbonate content of minerals - use only 5 or 10% HCl - be careful with the 10% - it is strong enough to cause some burning if left in contact with the skin). The HCl will react if calcium carbonate is present by fizzing just like carbonated beverages. No calcium carbonate, no fizz.
I guess the question is, if there is no calcium carbonate present in Reptisand, how can the gut lumps from Reptisand you are seeing be coming back 50% calcium carbonate? Could it be calcification in the gut? Sort of like gall or kidney stones? With a silica sand lump acting as a seed for the calcification?
It would sort of make sense - calcium carbonate is a soft mineral, the grains round easily, no sharp edges, and stomach acids would erode and round the grains even more... and yet silica (quartz) is a much harder mineral, and is much more likely to have sharp jagged edges to the grains. Whether by coincidence, or design, calcium carbonate present in the gut might precipitate out and adhere to the quartz grains, increasing the size of the lump, and causing impaction.
Please note this is just a theory, and I'm neither a vet, nor a herpetologist. The mineralogy of the theory is sound, but it's an educated guess - I'm not that familiar with the biology of herp digestive tracts. 
I'm just trying to do right by my new additions.
BTW, what substrate does everyone recommend for beardies (or is the jury still out)? The pair I recieved had been kept on "marine sand" but the texture was odd, the grains seemed large, but they appeared flat, so the effect was like light, fluffy, granular snow. There wasn't much dust, but the beardies kicked the stuff everywhere including into their food and water dishes, so I changed it right away to some standard white sifted playsand from Home Depot. There appears to be no dust, and it has a firmer, denser texture that the beardies haven't been kicking around. But I'm still not sure it's "safe" for them to be living on.
:I've spent 15 years assisting in bowel resections and preparing gut contents for biopsy, and Reptisand gut lumps usually come back as being over 50% calcium carbonate. Some are as high as the low 80's in percentage. Even pure calcium carbonate only comes back as being 85-90% calcium once it's formed into a gut lump. There are always bits of food, digestive enzymes, stomach acids, etc. making up the rest.
