A classic rarity Scinde Dawk, India’s first adhesive stamp is truly a hidden gem with its high demand and price. Find out its facts on this episode of Hidden Treasures.<br><br> Hidden Treasures is a series of mini-documentaries which holds the gems of notaphily, numismatics and philately industry. With the help of the newly established online museum, www.mintageworld.com, this series discloses information about the most expensive and exquisite stamps, coins and notes sold across the world. <br><br> Promoted by the “Ultra” group, mintageworld.com is the first website of its kind in the world, where all the three fields have been brought under one roof.