Do black olives have antioxidants? Yes, but the amount the have is much less than other varieties. The types they have include hydroxytyrosol (making up roughly 50% of their antioxidant content), vitamin E, trosol, oleuropein, oleonalic acid, and quercetin. They contain almost no vitamin C, A, K, or those in the B complex.
When it comes to minerals, black olives are a rich source of iron, copper, and a moderate source of calcium. Because of the way they are processed, one needs to be careful consuming them in abundance because of their typically high sodium content from the brine. The healthiest type based on ORAC value is the Kalamata olive.
As far as the sample used in this test, it was Mario's brand. The product was procured in Norway however the country of origin for the olives was Spain. Three different brands of black olives were tested and their ORAC values ranged from 230 to 890. None had the stone/pit intact.
Research Support, Non-U.S. Gov't: Carlsen MH, Halvorsen BL, Holte K, et al. Nutrition Journal NIH Jan 2010