Shiva Purana
सुप्रलिप्ते महीपृष्ठे दर्पणोदरसन्निभे ॥ अरत्नियुग्ममानेन चतुरस्रं प्रकल्पयेत् ॥ २ ॥
It was well smeared on the ground and looked like a mirror belly A square measurement of a pair of gems should be arranged.
english translation
supralipte mahIpRSThe darpaNodarasannibhe ॥ aratniyugmamAnena caturasraM prakalpayet ॥ 2 ॥
hk transliteration by Sanscript