Precious Stones Puns

Took my precious grandparents to Cold Stone for a late night snack. After waiting line, trying many samples and finally ordering and getting our ice cream, my grandma goes to pay. After some searching, she hands the cashier her rewards card and continues to search for her money. After a little more fumbling, she looks up to see the cashier with a funny look on her face and tells my grandma she can't use that card. My grandma is confused and asks, "why, is it expired?" To which the young girl responds, "no, it's just that we're not Ohmaha Steaks."

My grandma is super embarrassed and my grandpa turns to me and says, "it seems your grandma has a case of cardszheimers."

This morning he goes, "What's the word for the process of accounting for precious stones?

..........crystal math."