Defn: A mineral of a black color, submetallic luster, and high specific specific gravity. It is a niobate (or columbate) of iron and manganese, containing tantalate of iron; — first found in New England.
COLUMBIUM
Co*lum"bi*um, n. Etym: [NL., fr. Columbia America.] (Chem.)
Defn: A rare element of the vanadium group, first found in a variety of the mineral columbite occurring in Connecticut, probably at Haddam. Atomic weight 94.2. Symbol Cb or Nb. Now more commonly called niobium.
COLUMBO
Co*lum"bo, n. (Med.)
Defn: See Calumba.
COLUMBUS DAY
Co*lum"bus Day.
Defn: The 12th day of October, on which day in 1492 Christopher Columbus discovered America, landing on one of the Bahama Islands (probably the one now commonly called Watling Island), and naming it "San Salvador"; — called also Discovery Day. This day is made a legal holiday in many States of The United States.
COLUMELLA
Col`u*mel"la, n. Etym: [L., dim. of columen column. See Column.]
1. (Bot.) (a) An axis to which a carpel of a compound pistil may be attached, as in the case of the geranium; or which is left when a pod opens. (b) A columnlike axis in the capsule of mosses.
2. (Anat.)