The Chief tells Max that the circus has been responsible for depletion of industrial diamonds. However, the diamonds recovered by Max & 99 are cut and polished gems, not rough industrial stones, and are large enough that they would be counted among the world's largest gem-quality diamonds.
When Raymond is throwing two knives at Max being held by Hondo, these strike what look like two protective boxes - one on each arm - that suddenly appear under the sleeves of the strongman's costume.