Could be ketamine. We cant ID your susbtance as their is no way of knowing for sure without a test kit. Dab a small bit on your finger on it and put on your tongue, and if it makes you want to gag, you may well have MDMA haha. I've had very brown and very pale MDMA crystals that was more cylindrical than shardy, almost like pebbles, so theres no way of knowing unless you test it, either through a kit or through taste