Raver32 writes to mention that two nearby asteroids may be evidence of a
new class of asteroid or long eroded mini-world. Mineral evidence gathered using photometric data shows these asteroids to contain basalt not normally found in asteroid belt objects.
"The lack of basalt and another mineral, olivine, in asteroid belt objects has long puzzled scientists. These two minerals would have formed the crust and mantle, respectively, of belt objects the size of Vesta or larger; theory predicts that more than half of all asteroids should be composed of one or the other of these substances"