Adamant crystal

Adamant crystal is very tough stuff from the IDW portion of the Generation 1 continuity family.

Adamant crystal is a substance whose hardness rating is in the top percentile for the Transformers' region of space.

Fiction

IDW Generation 1 continuity

After he was shot through the chest and nearly died, Perceptor constructed a more impregnable breastplate out of adamant crystal for himself. Lost & Found