oölite

from The Century Dictionary.

• noun A granular limestone each grain of which is more or less completely spherical, and made up of concentric coats of carbonate of lime formed around a minute nucleus, which is usually a grain of sand: so called from the resemblance of the rock to the roe of a fish.
• Same as oölitic.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Geol.) A variety of limestone, consisting of small round grains, resembling the roe of a fish. It sometimes constitutes extensive beds, as in the European Jurassic. See the Chart of geology.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun Alternative form of oolite.