The Brief: Expensive jewelry, typically diamonds. Can also refer to crystal meth. Not to be confused with "icing" someone.
“Ice” is a slang term for diamonds and expensive jewelry. Someone with an excessive amount of diamonds would be “dripping” in ice, and an “iceburg” is an even greater amount of diamonds.
Ice on my neck, I’m the coolest. – Post Malone
Ice can also be a street term for methamphetamines or crystal meth.
The term “icing” someone refers to a common practice among college students of hiding a bottle of alcohol somewhere for a particular person to find. When they find the drink, they’re forced to take a knee and chug the whole bottle.