A large Chromium chunk (like the one you are asking) in metal form is not dangerous, only in powder it can become more dangerous, since it can oxidize more rapidly and an acidic sweat (because of the bacteria living in the skin) during handling can react with it, or in the hexavalent form ( for instance, dissolved as a salt) it is also dangerous. To avoid intoxication (and sample contamination, because you want a cleaner-as-possible sample) you must wear latex gloves during handling procedures, preferably without powder (powderless).

Sorry Maud. pol = inch. I mean toxic or explosive.

Chrome has been a standard constituent of metal alloy implants for ca. 60 years that helps them be low in toxicity. For example the "gold standard" for the femoral heads of total hip replacement implants is a Co-Cr-Mo alloy. Co and Fe based implant alloys get their corrosion resistance and related tissue compatibility from Cr in their compositions. Cr helps form surface oxides that are strong, adherent and continuous (unlike e.g. the flaky, broken surface on an ordinary piece of iron exposed to water or saline).