oolite (n.)youdaoicibaDictYouDict[oolite 词源字典]
"rock consisting of fine grains of carbonate of lime," 1785, from Modern Latin oolites, from oo-, comb. form of Greek oon "egg" (cognate with Old English æg, see egg (n.)) + lithos "stone" (see litho-). So called because the rock resembles the roe of fish.[oolite etymology, oolite origin, 英语词源]