I purchased 50 lbs of this gravel for my tank and I can easily say that this is the worst gravel I have ever purchased. I bought the black gravel. Mixed into the gravel were pieces of other colored gravel like pink, purple, red, blue, etc. one or two would not have been an issue, but there was enough that it made it very distracting. I probably picked out 100+ pieces. There was also a significant amout of enamel chips (flat pieces of layered enamel that look like they had chipped of the inside wall of the container that was being used to coat the gravel) and even after double rinsing, it left a significant oily residue in the water. Then, when doing gravel washes, the gravel chips and the enamel comes off leaving polka-dotted gravel. Some of the gravel appears to be made of a chalk-like material as it dissolves into white dust and an enamel shell after being washed. I plan on replacing with new gravel.
It's inexpensive, but this is an excellent example of "you get what you pay for".