The is a specialized tool used by diamond professionals to objectively measure the color of rough diamonds and predict their final grade after polishing. Invented by industry pioneer Zvi Yehuda in 1977, it remains a standard for minimizing human error and maximizing the yield of rough stones. Key Functions and Benefits
If Zvi Yehuda was a graduate of the Hebrew University of Jerusalem or a collaborator with Prof. Yoel Ariav (optical metrology), his colorimeter might have remained a prototype or limited-run device , never mass-produced. Today, surviving units could be found in old university labs or private collections of vintage scientific instruments.
The Zvi Yehuda Colorimeter is widely used by diamond miners, manufacturers, and laboratories globally, including major hubs in Israel, Belgium, and India. By removing the "guesswork" from rough diamond purchasing, the tool allows traders and manufacturers to evaluate the potential value of a stone with scientific certainty. It also plays a critical role in maintaining a "stone signature" that follows a diamond from its raw, rough form through to the final polished product. History & Heritage - Yehuda.com zvi yehuda colorimeter
: Typically show a 100% blue fluorescence under specific test conditions.
To understand the colorimeter, one must first understand its creator. Zvi Yehuda (1936–2014) was an Israeli-born gemologist and physicist who revolutionized how the trade looked at color. Working out of the famous "Ramat Gan" diamond district in Israel, Yehuda recognized that the human eye is an incredible, but inconsistent, detector. Fatigue, lighting conditions, and even the color of a grader’s shirt could alter a gem’s perceived color. The is a specialized tool used by diamond
Some advanced configurations can also categorize "Fancy Yellow" stones into groups like Light, Intense, or Vivid Fancy. Whiteflash Current Models & Specs The colorimeter is manufactured by Zvi Yehuda Ltd
in Israel and typically comes in two primary versions based on stone size: Tradeindia Model F-50 Model F-1000 Stone Size Range 0.30 to 50 carats 0.30 to 1000 carats Color Range D to K colors D to K colors Connectivity USB / Integrated with OGI Systems USB / Integrated with OGI Systems Industry Impact History & Heritage - Yehuda.com Yoel Ariav (optical metrology), his colorimeter might have
As color measurement technology continues to evolve, we can expect to see new and innovative devices that build upon the foundations laid by the Zvi Yehuda Colorimeter. Some future developments and trends in color measurement technology include: