Shiva Purana
उत्तरे तस्य सरसस्तीरे कल्पतरोरधः ॥ वेद्यां वज्रशिलामय्यां मृदुले मृगचर्मणि ॥ १८ ॥
On the northern bank of the lake is the Kalpataru tree. The altar was made of diamond stone and soft deer skin.
english translation
uttare tasya sarasastIre kalpataroradhaH ॥ vedyAM vajrazilAmayyAM mRdule mRgacarmaNi ॥ 18 ॥
hk transliteration by Sanscript