Matsya Purana — Cosmography of Śākadvīpa and Successive Dvīpas: Mountains
शाकद्वीपस्य विस्ताराद् द्विगुणेन समन्वितः तत्रापि पर्वताः सप्त विज्ञेया रत्नयोनयः //
śākadvīpasya vistārād dviguṇena samanvitaḥ tatrāpi parvatāḥ sapta vijñeyā ratnayonayaḥ //
That (next) continent is endowed with an extent twice that of Śākadvīpa; and there too are to be known seven mountains, which are sources (mines) of gems.
This verse is not about Pralaya; it belongs to cosmographic mapping of the world-continents (dvīpas), emphasizing proportional expansion and the presence of gem-bearing mountain ranges.
Indirectly, it supports the Purāṇic ideal that a ruler should understand sacred geography and the distribution of natural resources (ratna-yoni), which underpins orderly governance, trade, and protection of wealth.
No direct Vāstu or ritual rule appears here; the key takeaway is the Purāṇic concept of “ratna-yoni” (gem-sources), often used in later traditions to sacralize mountains and resource-bearing landscapes.