[quote=@Kafka Komedy]
Hey, Loki, how much control do most Gems have over their weapons? Could Sard shrink down his shuriken at will?
[/quote]

Depends on the Gem. Garnet was able to enlarge her Gautlets in that one episode when Steven thinks about what Garnet did that day. So, it you want your Gen to be able to do it you can. It just had to make sense with your weapon. A spear should not be able to grow larger, but you weapon can.