I would suspect that what you thought you were buying as Damascus Earth was a corruption of Diamotaceous Earth. I have never seen any reference to Damascus Earth as a pesticide and a quick search for "Damascus Earth" brings up mostly information about Diamotaceous Earth.

Here is a link that might be useful: Diamotaceous Earth

Yes I did a search for this and came up with the link you posted during my search. I use to buy Damascus Earth at Lowe's and Home Depot when I had a big garden. I quit gardening a few years ago due to disabilities and fire ants. I have had back surgery and not able to bend a lot or stoop. Then 2 years in a row, fire ants wiped out my whole garden--they tunneled under my garden and nested in the roots of my plants and ate the roots. So between my disabilities and the fire ants, I just gave up. What I am doing right now is only for 3 plants and they are all in 55 gallon drums, sitting on a hard plastic board. I put window wire screening in the bottom of the barrels to keep the fire ants out of the drainage holes but I need something organic to go on top of the soil surrounding my plants. I found in the past that Damascus Earth worked real well for most of my pest problems. I have to really keep the barrels moist because of all the potting soil in it and since it is dry here, the fire ants will find these barrels very attractive--thus, I need something to go over the soil in the barrels to keep them out. I just don't want to buy anything that is harmful and even though I read up on Diatomaceous Earth, I am not sure if it is as harmless as Damascus Earth.
Thanks for trying to help,
Sheila

I really don't think that there is such a product as Damascus Earth. You can buy the horticultural grade DE (diatomaceous earth) at Lowe's and Home Depot. Be sure to stay away from the stuff for swimming pools. It is NOT the same as the horticultural DE that you'll find in the garden center aisles. Don't let the incredibly 'helpful' employees steer you in the wrong direction.

rihzo: There may not be a product called by that name now, but there was a product call that a long time ago--maybe they just changed the name to Diatomaceous Earth now. The link that I posted shows a Commenter, named, "nepherym", 5th comment, making a statement about Damascus Earth--this comment was made in 2009, so maybe it was still around at that time. But as I said above, maybe they just took the product and renamed it Diatomaceous Earth since they both work the same way. I will try and get some at Lowe's or Home Depot and try it out.
Thanks,
Sheila

Here is a link that might be useful: Damascus Earth

Damascus earth is used for pool filters while Diatomaceous earth is food grade