Shiva Purana
कार्तिक्यां वैद्रुमं लिंगं वैदूर्यं मार्गशीर्षके ॥ पुष्परागमयं पौषे माघे द्युमणिजन्तथा ॥ ७५ ॥
On the day of Kārttikī one should worship Vaidruma, and on the month of Margaśīrṣaka one should worship Vaidūrya. It is made of flowers and gems in the month of Pausa and Magha.
english translation
kArtikyAM vaidrumaM liMgaM vaidUryaM mArgazIrSake ॥ puSparAgamayaM pauSe mAghe dyumaNijantathA ॥ 75 ॥
hk transliteration by Sanscript