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The material gives a truly unique opportunity to ascertain the little known and understood mechanics behind naturally occuring colour-change minerals.
The material is all color stable, as I have had a fair amount on top of my roof for the past 2 years with no change whatsoever.
These garnets (called dinner-bucket garnets locally) are from the dinner-bucket ridge mine in northern Idaho, USA. Thus far we have mined this property for the past two years, recovering a considerable amount of facet rough. The garnet is unique, in-that in indirect daylight (or reflected day light) they appear violet and in incandescent or directly transmitted daylight appear pinkish-red (raspberry). Upon heating they lose this colour-change, turning progressively oranger beginning at about 470 grade C
A bright blue transparent metallic coating begins to appear on the stones at 490 grade C, (more easily seen in indirect light) turning a transparent gold color at about 650 grade C, and an opaque red-brown at about 800 grade C. All of this performed in a completly uncontaminated heating environment. This coating has an apparent hardness of 7. The true underlaying colour is now a purplish-red.
For more information contact
Jesse Williams, P.O.Box 331, Lewiston, Idaho 83501,USA
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