Assertion: chrysoberyl's index | /r/HasProperty | measured by sodium light
Facets:
Source sentences:
text: The refractive index of turquoise (as measured by sodium light, 589.3 nm) is approximately 1.61 or 1.62; this is a mean value seen as a single reading on a gemological refractometer, owing to the almost invariably polycrystalline nature of turquoise.
text: The refractive index of Canadian material (as measured via sodium light, 589.3 nm) is as follows: