With the advent of modern methods of non destructive/semi non destructive such as LA_ICP MS (Laser Ablation, Induction Coupled Plasma, Mass Spectrometer) the trace element chemistry of tourmaline has become much more accessible. Elements such as lead and the rare...
In this post I will limit myself to a simple truth that has not been picked up by the internet and how it continues to propagate an older theory of color change that CAN NOT BE TRUE. I will not write about the proposed theory of why color change occurs in gemstones,...
Copper is not a common chromophore in gemstones. A chromophore is some impurity or imperfection that causes the gemstone to have color. With the discovery that naturally occurring feldspar can be enhance threw the diffusion of copper into its matrix, it followed for...
On this page I will present my observations on color change in tourmaline. I will be covering the following four spectral areas of change, red to orange, yellow/brown to green, green to blue, blue to purple (Laurellite). The last one is a recent discovery, since the...
This dark flash driven green emerald cut is a Dravite, the species, and displays the usambala effect. It appears to be eye clean and weighs 1.12 carats. This is the tourmaline in my collection that I will use in the following discussion on this page. It weighs 1.12...
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