These are faceted golden laser garnets (Ce+Nd Yttrium Aluminum Garnet). Some fluoresce pink and others fluoresce green-yellow, all have a rich golden-yellow base color that shifts depending on the illumination.
We have a special on 10mm stones with light chipping--they were shipped without appropriate paddingt
This is an unusual lab created garnet, YAG doped with both cerium and neodymium. Neodymium makes YAG a versatile laser crystal, and Nd YAG lasers are the most versatile and widely-used. While the original Nd YAG lasers only added Nd it was soon discovered that Ce could act as a booster to its power. This means that depending on the application you might see crystals that only have Nd or ones that are almost entirely Ce with just a pinch of Nd. Fortunately for us only the middle portion of the garnet crystals can be used for lasers and we were able to buy some of the unused tops to repurpose as gems.
Pure Nd gives a color shifting purple-pink color while pure Ce gives a rich fluorescent yellow color--when the two are mixed you get an unusual golden yellow color that shifts depending on the lighting. In sunlight it has a strong golden hue while some indoor lights will make it more pure yellow or more orangeish, and on a black background it sometimes takes on a green cast.
These stones also show unusual dual fluorescence, with a mix of bright yellow and pink under shortwave UV and yellow-green under both blue light and shortwave UV.
YAG has a high hardness of 8.25-8.5 and no durability issues. It is ideal for use in jewelry.
