The orangenacre mucket is a medium-sized mussel, up to 90 mm in length. The shell is oval in shape, moderately thick, and inflated. The posterior margin of the shell of mature females is obliquely truncate (shortened). The nacre is usually colored orange, rose, pink, or occasionally white. The periostracum varies from yellow to dark reddish brown, and with or without green rays (68 FR 14752).