What is this pill - round yellow pill diamond imprint?

Pill imprint Diamond is : Ecstasy (MDMA).

Ecstasy (MDMA ,3,4 methylenedioxymethamphetamine) is a synthetic, psychoactive drug chemically similar to the stimulant methamphetamine and the hallucinogen mescaline. Street names for MDMA include Ecstasy, Adam, XTC, hug drug, beans, and love drug. Ecstasy is an illegal drug that acts as both a stimulant and psychedelic

Read more at: https://www.drugs.com/illicit/ecstasy.html

Pill image:

www.erowid.org/chemicals/mdma/mdma_images_gallery3.shtml