Anandakanda 2.8.17

2.8.17

<pearl:: origin>
mātaṅgoragamīnapotriśirasastvaksāraśaṅkhāmbubhṛcchuktīnām udarācca mauktikamaṇiḥ spaṣṭaṃ bhavedaṣṭadhā /
chāyāḥ pāṭalanīlapītadhavalāstatrāpi sāmānyataḥ saptānāṃ bahuśo na labdhir itaracchaukteyakaṃ tūlvaṇam //

The pearl gem clearly arises from eight places: the belly of elephants, serpents, fish, boars, the heads [of clouds], bamboo, conch shells, and oyster shells.
Its lusters are pale-red, blue, yellow, and white; even there, generally,
seven of them are not commonly obtained, but the oyster-born one is abundant.