The word plagioclases 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: 22
Highest Scoring Words With Friends™ Plays In The Letters plagioclases
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Seven Letter Word Alert: (42 words)
alcogel, aliases, apogaic, apogeal, apogeic, callose, capless, celosia, coalise, collage, collies, epilogs, gallops, gapless, gelcaps, glacial, glioses, goalies, gospels, ligases, lipases, lipless, locales, logical, ossicle, paellas, palaces, palsies, pascals, passage, pelagic, pillage, polices, scallop, scalpel, scapose, scillas, socials, solaces, spacial, special, splices