American Weigh Gemini-20 Portable Milligram Scale, 20 by 0.001 G for $30.49

Take a handy little digital scale on the go and weigh items up to 20 grams in 0.001 gram increments. The little scale is great for weighing precious gems and other valuables. Its flip-down shield protects the delicate weighing surface. A removable stainless-steel weighing platform makes removing samples easy. The scale's included carrying case comes with tweezers, a tray, and a calibration weight. The unit is powered by 2 AAA batteries, which come included, and is backed by a 10-year warranty.