There is something weird with these drops or they dont work as I think should work. I mainly got elemental ones from class abilities (sunspots, nades) or weapons like cloudstrike thunder kills. Weapons gave auto, precision, multi, explosion etc most of the time. Supers gave superb. Orb ones not certain I think I got few when I collected the orb after weapon kills, but that could have been icon just popping up at the same time. I had hard time getting solar ones from free world, but got mine to drop after loaded to strike, went to lost sector and killed mobs with titan solar nades and sunspots. I did not record gameplay so they might have dropped without me noticing.