This is a list of Gem technology that has appeared but holds no significant nor recurring role.
Yellow Diamond Flare Signal
The Yellow Diamond Flare Signal is a flare signal that emitted from Peridot's Escape Pod in "Joy Ride".
The Yellow Diamond Flare Signal displays a complex web of geometric shapes overlapping each other into the sky when fired. The signal is composed entirely of straight lines of yellow light. Diamonds, squares, rectangles, and other various polygons can be seen within the signal.
It is unknown whether or not other Gem ships from Homeworld, such as the Gem Warship, possess the ability to emit the Yellow Diamond Flare Signal.