This was the chief substitute for diamond in the 1960s. It has now been replaced by other products, mainly cubic zirconia.

Appearance Perfectly transparent and colorless and singly refractive like diamond, it is usually seen cut into brilliants; more rarely, it is given a step cut. Its luster is about the same as that of colorless zircon and greater than that of corundum and spinel. Being hard but not brittle, it is easily given a high polish and sharply defined edges. But low dispersion makes these stones look a bit lifeless, particularly those with a step cut.

Distinctive features Because YAG's refractive index is quite a bit lower than that of diamond, if a brilliant cut stone is viewed from above and tilted gradually, a characteristic dark area will appear in the table facet (opposite the observer), corresponding to certain facets of the pavilion which let the light through instead of reflecting it. Furthermore, if the stone is viewed from the table facet (with a lens or microscope) the distinct reflections of the table and crown facets will not be visible as they are with diamond. Also, if step cut stones are placed upside down with the table facet resting on a printed page, the letters will be visible through it. The girdle is not finished like that of diamond; it is not cylindrical and is usually striated, as if it had been filed; yet, despite this rough finish, it looks fairly transparent. A hardness test using a corundum-tipped pencil (9), which is midway between the two, will readily distinguish YAG from diamond.

Cost One of the lowest, equal to that of the least expensive synthetics. The cost of the raw material is, in fact, very low and it is much quicker and easier to cut than diamond, being softer and without any tendency to brittleness.


Copyright 2005 © Gemstone Jewelry

eXTReMe Tracker


We only provide the most brilliant natural Precious Gemstones and diamonds, highest quality pearls and rare precious gems are combined and set with 18ct gold rings & Sterling Silver Jewelry chains to create the finest and most elegant designer jewelry.