Optic Character
Embed This Widget
Add the script tag and a data attribute to embed this widget.
Embed via iframe for maximum compatibility.
<iframe src="https://gemfyi.com/iframe/glossary/optic-character/" width="420" height="400" frameborder="0" style="border:0;border-radius:10px;max-width:100%" loading="lazy"></iframe>Paste this URL in WordPress, Medium, or any oEmbed-compatible platform.
https://gemfyi.com/glossary/optic-character/Add a dynamic SVG badge to your README or docs.
[](https://gemfyi.com/glossary/optic-character/)Use the native HTML custom element.
Definition
The fundamental optical classification of a gemstone as either isotropic (singly refractive) or anisotropic (doubly refractive), and if anisotropic, whether it is uniaxial or biaxial.
Detailed Explanation
Isotropic gems belong to the cubic crystal system or are amorphous; they have a single refractive index. Anisotropic gems have two (uniaxial) or three (biaxial) principal refractive indices. Uniaxial gems (trigonal and hexagonal systems, including corundum and quartz) have one optic axis along which light is not split. Biaxial gems (orthorhombic, monoclinic, triclinic systems, including topaz and alexandrite) have two optic axes. Optic character is determined using a polariscope or conoscope and is one of the primary steps in systematic gem identification.