Kautilya's Arthashastra 2.13.4

2.13.4

kiñjalkavarṇaṃ mṛdu snigdham anādi bhrājiṣṇu ca śreṣṭham, raktapītakaṃ madhyamam, raktam avaram //

That which is of the colour of the petals of a lotus, ductile, glossy, incapable of making any continuous sound (anádi), and glittering is the best; that which is reddish yellow (raktapíta) is of middle quality; and that which is red is of low quality.