In 1983 the Michelsen family set about developing a scientific method of establishing the value of any gemstone starting with the cost of the raw material. Most rough dealers know the worth of their product, but even if they didn't the broker or cutter that bought it from them would know. From this an equation was developed incorporating yield from the crystal shape, cost of production, cost of distribution, supply and demand for each product and lastly the value of the dollar against the currency from whence the raw material originated.

In the begining, this index was only available to our students at Gem Spectrum, but it soon became apparent that this information was required by other brokers, goverment agencies, appraisers, auctioneers, retailers and wholesalers. We have now made this service available on the internet and would encourage our subscribers to avail themselves of this as revisions are made on a continuous basis. We have enjoyed our fifteen years of service to the industry and look forward to a long association with our new and existing subscribers.