These stones are sold on 8" strings. According to Wikipedia Sodalite is a rich royal blue mineral widely enjoyed as an ornamental stone. Although massive sodalite samples are opaque, crystals are usually transparent to translucent. Sodalite is a member of the sodalite group and together with hauyne, nosean and lazurite is a common constituent of lapis lazuli.
Discovered in 1806 in Greenland, sodalite did not become important as an ornamental stone until 1891 when vast deposits of fine material were discovered in Ontario, Canada. It has since been named Princess Blue after Princess Patricia who, upon visiting Ontario some time after its discovery, chose sodalite as interior decoration for Marlborough House in England.