Small Treasure is a term used to describe a valuable item that is small in size. The term can be used to refer to a variety of items, such as jewelry, coins, or antiques. In this particular crossword, the solution for Small Treasure is 'PEARL', which is a type of gemstone that is often found in oysters and mussels. Pearls are highly valued for their beauty and rarity, and have been used in jewelry for centuries.