Someone help identify this for my dad. (Yea, I think I know what out is 🤦‍♀️)

The story- my sister has a bad substance issue. And so does her partner. My father is older and unfortunately very naive. He swears her partner gave it to him and said it was a THC edible. he’s been a pothead his whole life, so am I. Listen I could be wrong man we come up with weird stuff. Yall please seriously, help my thread here and lmk what this sounds like to you. He won’t listen to me, he trusts her beyond relief. (Just realized can’t add photos) It’s a blue tablet, literally exact shape and size and color of a xan, with the number 5 on each 1/4th.