This Presidium Gauge is a perfect tool for estimating the size and carat of mounted and loose gemstones.

This Presidium Gauge measures the dimensions and estimates the weight of loose and mounted gemstones with precision, speed, and ease. After entering the weight and the measurements of a gemstone, PGCG narrows its identity by computing its S.G. value. With PGCG's computer interfacing, gemstone measurement records can be easily imported and printed. PGCG also comes with a CD that lists the S.G. value, R.I. value and hardness measurements of 133 common gemstones in the market for handy reference. Key features include: measures up to 25.0 mm with .01mm accuracy, calculates estimated weights for 74 gemstones in 9 different shapes, direct reading of estimated weight for round brilliant-cut diamonds, computer interface display with USB connectivity, specific gravity dictionary for quick and easy reference