Matsya Purana — The Cave-Sanctuary: Jewel-Lake
नानारत्नैरुपचिता जलजानां समाश्रयः कपर्दिकानां शुक्तीनां शङ्खानां च महीपते //
nānāratnairupacitā jalajānāṃ samāśrayaḥ kapardikānāṃ śuktīnāṃ śaṅkhānāṃ ca mahīpate //
O king, it is richly filled with many kinds of gems, being the common abode of aquatic creatures, of kapardikā (cowries), of pearl-oysters, and of śaṅkha (conches) as well.
This verse is descriptive rather than apocalyptic: it highlights the ocean/waters as a sustaining reservoir of life and treasures, not a direct account of Pralaya.
By addressing the king and noting the abundance of gems and ritual shells (conch, cowry, oyster), it implies the ruler’s duty to protect natural resources and regulate their auspicious use in economy and rites.
Śaṅkha (conch) and śukti (oyster/pearl-shell) are classic ritual materials; such verses support temple-ritual procurement and purity symbolism associated with waters in Vastu and consecration contexts.