  Although spectral surveys and spacecraft missions provide information on
small bodies, many important analyses can only be performed in terrestrial
laboratories. For now, the total number of parent bodies represented in our
meteorites collection is estimated to about 150 parent bodies, of which 50
parent bodies represented by the poorly studied ungrouped chondrites. Linking
ungrouped meteorites to their parent bodies is thus crucial to significantly
increase our knowledge of asteroids. To this end, the petrography of 25
ungrouped chondrites and rare meteorite groups was studied, allowing grouping
into 6 petrographic groups based on texture, mineralogy, and aqueous and
thermal parent body processing. Then, we acquired visible-near-infrared
reflectance spectroscopy data, in order to compare them to ground-based
telescopic observations of asteroids. The reflectance spectra of meteorites
were obtained on powdered samples, raw samples and polished sections. Our
results showed that sample preparation influences the shape of the spectra, and
thus asteroid spectral matching, especially for carbonaceous chondrites.
Overall, the petrographic groups defined initially coincide with reflectance
spectral groups. We define links between some of the studied ungrouped
chondrites and asteroid types that had no meteorite connection proposed before,
such as some very primitive type 3.00 ungrouped chondrites to B-type or Cg-type
asteroids. We also matched metamorphosed ungrouped carbonaceous chondrites to
S-complex asteroids, suggesting that this complex is not only composed of
ordinary chondrites or primitive achondrites, as previously established, but
may also host carbonaceous chondrites. Conversely, some ungrouped chondrites
could not be matched to any known asteroid type, showing that those are
potential samples from yet unidentified asteroid types.
