Bengali inscriptions on both sides, closely copying the older 1/2 rupees from Cooch-Behar, issued by Devendra Narayana (1763-1765) and Rajendra Narayana (1770-1772). This particular coin is made of almost pure copper (not silver or billon), but it can be attributed to the first striking period, ca.1839-1850. 20 mm, 4.20 grams. Nicholas Rhodes, Coinage of Bhutan, #1-12. Quite an exceptional specimen, rare this nice.