Continuing from here and here, a brief update on Pink Diamond related things as of Steven Bomb 3.

With the reveal of Sardonyx, we are now at four counts of Pearl bearing Diamond insignia - and all instances are connected to the past and long unused things, which she presumably never thought or had the need to fix.

1 - Holo-Pearl from Steven the Swordfighter

2 - The space suit from Space Race

3 - Half of Rainbow Quartz’s belly cutout (transformed from Rose’s star)

4 - Finally, Sardonyx’s shoes.

Additionally, the ancient spaceship visited in Friend Ship features the old four-part version of the Diamond insignia, same as the variant seen in the Sky Arena, giving us another pre-Rebellion source.

The interior of the ship is noticeably equipped with pink-hued Gem tech.

Pearl: What we see before us is an ancient interplanetary gem vessel. Homeworld Gems used these ships to travel across the cosmos and land here on Earth before the Warp Pads were built. But these ships landed here so long ago that there’s no way they can be functional.

Since we already know (from both Greg and Pearl) that Rose was involved in the Kindergarten project on Earth before she rebelled, this being one of the ships she and her forces initially arrived on seems pretty plausible to me.

Bonus: Rebecca Sugar’s SDCC teaser from her Instagam, in the form of jewellery.