Universal Specific Gravity Kit for your Electronic Carat Scale This "Electronic Scale" method/device is the best overall for Specific Gravity measurement. It is very accurate, providing that the Scale you use it with is sensitive enough, while the measuring process is quick and easy, overall. As seen on YouTube, just weigh your sample in "Air" (which is the same as weighing it on the platform of your Scale), and then weigh the sample in "Water." Then calculate SG by dividing the difference between the heavier Weight in Air and the lighter Weight in Water, into the Weight in Air. A simple Worksheet is provided for that purpose. Kit contains 3-way adjustable Beaker assembly, Weighing Pan assembly, Aluminum Stick reference weight (SG=2.70), Tweezers, Illustrated Instructions, Worksheets, and Table of Gems sorted by Specific Gravity. Your Scale must have minimum capacity of 50 carats, protruding Weighing Platform at least 1.5" across, openable or removable draft shield/lid for access from front and 1 side, and Tare function to Zero out Scale. This kit uses a 50mL Beaker as a water container, with approximately a 1.6" inside diameter. The "tared weight" of that portion of the kit that sits on the weighing platform is 40 carats SG accuracy depends on Readability or Minimum Weight spec of the scale you use with the SG Kit. Rule of thumb is Readability x factor of 50, so a Scale with Readability of .01ct will give accurate SG on items weighing down to .5ct (.01 x 50).