Tannins and human health: a review. Chung KT, Wong TY, Wei CI, Huang YW, Lin Y. Department of Microbiology and Molecular Cell Sciences, University of Memphis, TN 38152, USA. Tannins (commonly referred to as tannic acid) are water-soluble polyphenols that are present in many plant foods.
How to Cast Jewelry. Jewelry casting is a process of making jewelry pieces that involves the pouring of liquid metal alloy into a mold. It is usually referred to as lost-wax casting because the casting mold is created using a wax model that is melted away to leave a hollow chamber in the middle of the mold.
Base Metal. Base metal is a jewelry industry term for nonprecious metals used in costume jewelry, including copper, aluminum, brass, nickel silver, pewter and white metal, also called pot metal. Nickel silver is a silvery-white alloy resembling silver made from nickel, zinc, copper, iron, manganese and sometimes lead.nlike fine jewelry, costume jewelry is made from nonprecious metals called base metals. Most of these are both beautiful and relatively benign. However, nickel can cause an allergic reaction, while the lead found in some alloys has been linked to far more serious conditions and is highly regulated.