Black holes suggest anti-matter has negative matter but is this true? I think anti-matter has positive mass - e.g. a positron and electron annihilate giving off 0.5MeV + 0.5MeV photons where these photons have a huge positive energy. If the positron had negative mass then there would be no 1.0MeV of photon energy created. But when 'explaining' evaporating black holes (e.g. https://en.wikipedia.org/wiki/Hawking_radiation#Overview)- matter [e.g. electron] and corresponding anti-matter [positron] are created out of 'the vacuum', If the electron is ejected, then the positron is absorbed in the black hole which loses mass. In this case the positron mass is negative. So does anti-matter have positive or negative mass-energy or both?