Matsya Purana — The Cave-Sanctuary: Jewel-Lake
तुत्थकस्य तु खण्डानि तथा शेषस्य भागशः राजावर्तस्य मुख्यस्य रुचिराक्षस्य चाप्यथ //
tutthakasya tu khaṇḍāni tathā śeṣasya bhāgaśaḥ rājāvartasya mukhyasya rucirākṣasya cāpyatha //
Likewise, take pieces of tutthaka and portions of the remaining ingredients in due measure; include also the principal rājāvarta and rucirākṣa.
This verse is not about pralaya; it belongs to a technical, Vastu/Śilpa-oriented passage listing mineral substances and their measured portions for practical use.
It supports the king/householder’s dharma indirectly: proper procurement and proportioning of materials is part of maintaining temples, public works, and consecrated spaces according to śāstric standards.
It indicates a prescribed recipe-like procedure—specific minerals (tutthaka, rājāvarta, rucirākṣa) are to be taken in pieces and in measured shares—typical of Vastu/Śilpa instructions for coatings, pigments, mortars, or consecration-related material preparations.