i couldn't find the spongebobXsmash comic strip about tilting the image to make a legit leak, so have this instead:

Also I would like to point out; Jasper over there has a gem destabilizer. Garnet broke those in half in Jailbreak.

She wouldn't be able to get another one since the hand ship, which has demonstrated to be capable of producing those, exploded into chunks and (I would assume) those type of weapons are modern gem technology which means she wouldn't be able to acquire one on Earth.

I could be wrong. She might've gotten lucky and find that piece of the ship still functioning or she has a spare inside her "gem storage pocket dimension thing" (assuming that all gems have those) or these things existed before and so there'd be some lying around in some ruins.