Roosevelt is quite a special meteorite, with an unusual H3.4 classification. There are only 7 meteorites known in the world with this H3.4 classification (5 from the Antarctic, Sharps and Roosevelt itself). Roosevelt is one of the most unequilibrated H chondrites yet known, and gives us useful information about the accretion of chondritic material. The low petrologic type is a hint that the original parent asteroid (or part of it) did not suffer any severe heating processes (which would lead to higher petrologic types).
Therefore, the material is very primitive and gives us an insight into the processes at work during the formation of the early solar system. Roosevelt is very gas-rich (noble gas) suggesting that this material came from the surface (regolith) of the parent asteroid.
Visually, cut sections of Roosevelt show a black matrix with dark chondrules and lots of metal flake.