An order was placed with the vendor for their normally advertised Mrock. I have received from them many times before. This time, it was just pure white dust. Could be baking powder or flour (maybe BK) given the consistency; I don't have a test kit at the moment. This is not what was ordered and is unlikely to be Mrock. Be careful when ordering.
You should have a test kit, the full suite. Don't consume anything a stranger on the internet has sent you without knowing what it is. You need the full suite to differentiate the MDxx's
You can't really judge MDMA by its appearance - not consistency nor color. You can find white powder that is more potent than tan rocks.