Matsya Purana — Description of Gomedaka and Puṣkara Dvīpas; the Lokāloka Boundary; Ocean Tide...
कूटैश्चित्रैर्मणिमयैः शिलाजालसमुद्भवैः द्वीपस्यैव तु पूर्वार्धे चित्रसानुः स्थितो महान् //
kūṭaiścitrairmaṇimayaiḥ śilājālasamudbhavaiḥ dvīpasyaiva tu pūrvārdhe citrasānuḥ sthito mahān //
In the eastern half of the island stands the great mountain Citrāsānu, whose many-peaked summits are wondrous—gem-like and variegated—rising from a network of rocky strata.
This verse is not about Pralaya; it belongs to the cosmographic description of the world, locating a great mountain (Citrāsānu) in the eastern half of the dvīpa and describing its jewel-like, rocky peaks.
Indirectly, such geographic catalogues provide the Purāṇic map of the sacred world that frames royal duties like pilgrimage patronage, protection of sacred regions, and ritual legitimacy tied to holy landscapes.
The verse does not give a direct Vāstu or ritual rule; its significance is descriptive—highlighting auspicious, gem-like mountainous terrain often treated in Purāṇas as sacred geography that later texts connect with tīrthas and temple sites.