The word rhinestone is playable in Words With Friends™, no blanks required. Because it is longer than 7 letters, you would have to play off an existing word or do it in several moves.
Words With Friends™ Letter Score: 14
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (35 words)
entries, erotise, estrone, heroine, heroins, heroise, heteros, histone, hornets, inshore, intense, interns, intoner, intones, introns, neither, nitrene, norites, orients, rehones, rennets, reshine, shorten, stonier, tenners, tension, therein, thereon, thinner, thiones, thrones, tinhorn, tinners, trienes, triones