  Olivine-dominated asteroids are a rare type of objects formed either in
nebular processes or through magmatic differentiation. The analysis of
meteorite samples suggest that at least 100 parent bodies in the main belt
experienced partial or complete melting and differentiation before being
disrupted. However, only a few olivine-dominated asteroids, representative of
the mantle of disrupted differentiated bodies, are known to exist. Due to the
paucity of these objects in the main belt their origin and evolution have been
a matter of great debate over the years. In this work we present a detailed
mineralogical analysis of twelve olivine-dominated asteroids. Within our sample
we distinguish two classes, one that we call monomineralic-olivine asteroids
and another referred to as olivine-rich asteroids. For the
monomineralic-olivine asteroids the olivine chemistry was found to range from ~
Fo49 to Fo70, consistent with the values measured for brachinites and R
chondrites. In the case of the olivine-rich asteroids we determined their
olivine and low-Ca pyroxene abundance using a new set of spectral calibrations
derived from the analysis of R chondrites spectra. We found that the olivine
abundance for these asteroids varies from 0.68 to 0.93, while the fraction of
low-Ca pyroxene to total pyroxene ranges from 0.6 to 0.9. A search for
dynamical connections between the olivine-dominated asteroids and asteroid
families found no genetic link (of the type core-mantel-crust) between these
objects.
