This unusual and striking 9ct gold and burnt Orange Tourmaline gemstone Marlin weighs 6.32grams and is around 5cm long. The Marlin is stamped and hallmarked. Please view the pics as they form part of the description. The Gemstone Tourmaline is the most colorful of all gemstones. It occurs in all colors, but pink, red, green, blue and multicolored are its most well-known gem colors. Scientifically, tourmaline is not a single mineral, but a group of minerals related in their physical and chemical properties.