Weighing Diamonds and Gemstones

Weighing Diamonds and Gemstones

Learn How to Best Weigh Diamonds

Legal for Trade Carat Scales

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Achieving fast and accurate results
Avoiding moving the scale

Waiting for the scale to warm up

JET Carat Scales 

Accurate and reliable - smart features for trusted diamond and gemstone weighing


JE Carat Scales 

All the basic functions you need for your daily diamond and gemstone weighing


WXTJ Microbalance

Unsurpassed accuracy for weighing for smallest precious samples


Additional METTLER TOLEDO Scales for Weighing Diamonds and Gemstones

Jewelry Microbalance

For highly accurate jewelry weighing

Tips and Tricks to Avoid Weighing Errors

Related Products

FAQ - Weighing Diamonds

Frequently Asked Questions on Weighing Diamonds


1. What is the difference between carat in gold weighing and carat in diamond weighing?

In relation to gold, carat, sometimes spelled karat, (k) is a measure of the purity of the gold. In relation to diamonds, carat (ct) is a unit of weight; 1 carat equals 200 milligrams.


2. What readability do I need for weighing diamonds?

In general, diamonds are weighed in carats to 3 decimal places so the readability required is 0.001 ct. For very small diamonds, a scale with a higher readability such as 5 decimal places, or even a microbalance with 6 decimal places may be required. METTLER TOLEDO's JET and JE carat balances offer the additional benefit of weighing to 4 decimal places in grams.


3. During my diamond weighing processes, it sometimes takes a while to get the weighing result. How can I get faster results?


4. Is calibration needed when weighing diamonds?

When weighing diamonds, periodic calibration is necessary to ensure ongoing accurate and reliable results. Calibrating your diamond weighing instrument will ensure that it reaches standards such as ISO, GMP/GMP, IFS and BRC. Documented calibration procedures verify the quality of measurements, and should be performed regularly throughout the balance’s lifetime. Calibration should not be confused with adjustment and must be repeated after adjustment/repairs.


5. Can I connect my carat scale to our internal network?

JET carat scales have 3 interface ports - USB host, USB device and RS232 - and are easy to connect to an internal network via the built-in PC Direct function. In addition, JET carat scales offer Bluetooth connection via the optional Bluetooth adapter.


6. How do I clean my carat scale?

METTLER TOLEDO carat scales are made from high-quality, chemically resistant materials and can therefore be cleaned with a commercially available, mild cleaning agent and a damp cloth or soft paper tissue. Use common cleaning agents such as 70% ethanol or isopropanol, or mild detergents. The weighing pan and balance base are made of stainless steel that is robust and chemically resistant, with the exception that it is not compatible with strong acids. Acetone should not be used, even for highly sticky substances, as it is not compatible with plastic handles, glued parts or the screen.

For more information on cleaning your carat scale, download our free cleaning guide.


7. I have heard about 'blood diamonds', but what does that mean?

Blood diamonds, sometimes referred to as 'conflict diamonds', are diamonds that have been traded to provide funds for war. The Kimberley Process Certification Scheme (KPCS) was set up following a meeting in Kimberley, South Africa involving South African diamond producers who wanted to find a way to eliminate the trade in conflict diamonds. The KPCS requires that the member countries in the scheme certify that their diamonds are conflict free. Members are also required to implement legislation for the export, import and internal control of diamonds. Members are only able to trade with other members. The Kimberley Process states that 99.8% of the trade in conflict diamonds is prevented through the actions of its members. The certificate that accompanies the purchase of a diamond by a member of the public should include KP certification.

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