Rub"stone` (?), n. A stone for scouring or rubbing; a whetstone; a rub.
||Ru"bus (?), n. [L.] (Bot.) A genus of rosaceous plants, including the
||raspberry and blackberry.
Ru"by (?), n.; pl. Rubies (#). [F. rubis (cf. Pr. robi), LL. rubinus,
robinus, fr. L. rubeus red, reddish, akin to ruber. See Rouge, red.] 1.
(Min.) A precious stone of a carmine red color, sometimes verging to
violet, or intermediate between carmine and hyacinth red. It is a red
crystallized variety of corundum.
Besides the true or Oriental ruby above defined, there are the balas
ruby, or ruby spinel, a red variety of spinel, and the rock ruby, a red
variety of garnet.
Of rubies, sapphires, and pearles white.
Chaucer.