In the original Crash game, where the colored gems were earned on the same way as the clear gems. The purple gem is obtained by breaking all the crates and not losing a life in Lights Out, which requires the yellow gem for it to be obtained. It opens up the purple gem path in Boulder Dash.
DM's Guide Crash Bandicoot 1 - Lights Out (Purple Gem)-0
The purple gem appears oblong shaped. In this game, it can be obtained in Bee-Having by reaching a secret area in the stage, which can be accessed by hopping to the top of a set of stairs made up of nitro crates. It opens up part of the multicolor gem route in Spaced Out. There is no special purple gem route in this game.
The sprite of the purple gem is exactly the same as in Crash 2. It can be obtained by completing the death route in High Time. It opens up the purple gem route in Tomb Time and part of the multicolor gem route in Bug Lite. Although a purple gem route was eventually going to be in Gone Tomorrow, it was changed to a green gem route instead.
The purple gem is featured as the prize in the Purple Gem Cup. Earning it also awards the player with Fake Crash. The purple gem cup can be unlocked by collecting all the purple CTR tokens, which are earned by completing the crystal challenges located in each area's battle arena. The purple gem cup pits the player against the bosses of the game on their respective tracks, in order.
The purple gem is once again featured as the prize in the purple gem cup, which now offers Zam as the other prize. It is run on the tracks Android Alley, Tiny Temple and Thunder Struck. The purple CNK tokens must be collected to unlock this cup, and again require the completion of the crystal challenge in each area's battle arena to unlock.
The purple gem reappears in the N. Sane Trilogy remasters of the first three games where it reprises the same role it had in the original versions of those games. It is custom drawn on the pause screen and looks the same throughout all three games.
Crash Bandicoot N. Sane Trilogy - Lights Out - Purple Gem Guide
Crash Bandicoot N. Sane Trilogy Bee-Having 100% Complete Purple Gem
Get the PURPLE GEM in High Time stage Crash Bandicoot 3 Warped (N. Sane Trilogy)
The purple gem reappears in Crash Team Racing: Nitro-Fueled where it reprises the same role that it had in the original version of Crash Team Racing. Fake Crash can also be unlocked after completing the cup.