a large mass or block of hard stone rooted in the ground. See MOUNTAIN.

ornithology, a species of Vultur.

Rock Crystal, in natural history, otherwise called sprig crystal, a name given to the third order of crystals, from their being affixed to a rock or other solid body. This kind of crystal is the most common of all others, and is what the generality of authors describe under the name of crystal of the flags. The clearest, purest, and most transparent that can be had is to be chosen; and to prove its genuineness, it may be tried with aquafortis; true crystal making no effervescence with that medium.

Rock-Fish. See Gobius.