GRADING REPORT AMM3489
- Identification: Assembled Natural Unheated & Untreated Ammolite on Fossil Shell
- Carat: 34.89
- Shape: One-sided Rectangular Freeform
- Measures: 34.17x19.44x5.07 (millimeter)
- Iridescence: Bright / Intense
- Color-Spectrum: Very Good
- Shift & Range: Good
- Scaling: Minimal
- Shape: Very Good
- Depth of Ammolite: 15%
- Origin: Canada, Alberta
Treatment: None (assembled gem)
Certificate No: IGI 350866943
Overall Grade: Very Good
Comment: Another new world of organic gemstones: ammolite, the fossil shell of a Devonian (400 million years ago) cross between shell-fish and octopus, in looks similar to their last living descendants, the much smaller tropical Nautilus. As with pearls or corals, not to mention opal, the grading of this gemstone could fill books, or a collectors' lifetime. To differentiate from the usual A, AA, AAA-grading, we separated their evaluation into: A) quality and intensity of iridescence, B) color-spectrum, C) shift & range of color, D) scaling plus E) shape and finally F) surface depth of the ammolite. Starting with the latter, ammolite is a composite gemstone similar to opal on matrix or doublets. The surface depth influences the quality of its color-play and the color spectrum. 'Scaling' evaluates the amount of splintered areas versus fully intact surfaces, here 'minimal' with a good in 'shape' regarding usability for jewelry, its size and form. 'Shift & Range' in this particular specimen is 180 degree (the top-side) and a 100% shift between different colors. The 'color spectrum', all possible colors, in this 34 carats is yellow, orange and green plus any mixes thereof. The intensity and strength of an ammolite's iridescence may be the most important feature, for which this gem was chosen to become our first entry. This last point must be judged in the front view, or what we'd call face-up in other gems. In this our first ammolite exceeds with a rich neon orange, seen in those images where the camera points straight onto the gem's surface, light reflecting from the back (1st below), which will be the most seen position in jewelry. From one side-view it appears rich green (2nd below), from the other red-orange, with yellow filling the gaps as the viewing angle changes. So much here to the grading of ammolites.
P.S. With supply limited by the occurrence of fossils, it is thought to be depleted in two or three decades. Using a DeBeer-style approach, ammolite would be a much better candidate than diamond for a monopoly without the risk of overproduction in mid-century (a free hint for VCs out there).
