Petco has their brand of black sand. It's not a real fine sand. I have used it in two tanks looks good and very clean. Reminds me of T grade color quartz. It might be rebranded Etes Perma color. They should have it in stores now. I appears to be readily available in Maryland.
If it's for a large tank I suggest the black diamond as previously mentioned. It is not recommended for any fish that burrows or sifts because it has sharp edges and will end up iritating and hurting the fish. But as long as you stick with only shimp I don't see a problem.
If it's a small tank just get one fo the overprices bags from a fish store.