I recently received 25g of MDMA from a German vendor who I don't want to name yet to avoid undue slander. But the pack went immediately to a buyer whole. This buyer claims to have done a marquis test which went straight yellow (methylone/mdpv).
On the buyer's side, he just provided a picture of the test and his report of a weak 1.5-2hr roll. The crystals were a dark tanish-brownish-almost-purpleish color. I have not personally tried the product. Price was also pretty cheap, $260 with tracked shipping.
On the vendor's side: 600 orders and 4.9/5 average. Only one negative review of poor quality recently.
Is the picture of the test and description enough to doubt the 600 reviews? Only reason I doubt it is because the buyer might be trying to get it for super cheap or something.
Marquis test expire after some time producing invalid results. Maybe this explains it.