jo crystal
A JO crystal is a jewel, usually in the form of an unrefined crystal pendant necklace, which amplifies the eroticism of a sexual encounter in some way. The term JO crystal is derived from a m4m listing that was posted on craigslist in 2008 titled "charge up and JO - 38 (houston)". The poster claimed that the crystal "contains an essence that gets charged when I jack it with a bro".