The unloading part of the cycle causing plastic deformation on the surface of the striation. These beetles are mostly glossy black with parallel striation on elytra. The colour is yellowish-white and the periostracum (surface) is silky with fine, concentric striation. The periostacum (surface) is ornamented with fine, even, concentric striation. Rock faces created by glacial striation offered ideal surfaces for art. The shell is yellowish to brownish, smooth or with fine striation. Gabriel is attired in flowing gold robes, done in striation that invigorates the angel's garment. The male is olive green with faint yellow leg striation. Groove or striation marks result from the continuous contact with the muddy bed. The striation marks on the shreds have been obliterated by constant use. The outer lip is broadly recurved, thin, and showing the fine external striation within. Within V1 there is a distinct band (striation). Striation images can also be uploaded to any existing national databases. The striation profile depends on the degree of loading and unloading in each cycle. A striation marks the position of the crack tip at the time it was made.