from The American Heritage® Dictionary of the English Language, 5th Edition.
- noun The property possessed by some solutions of showing different colors at different concentrations.
- noun The property possessed by some crystals of exhibiting two different colors when viewed along different axes.
from The Century Dictionary.
- noun In optics: A property possessed by many doubly refracting crystals of exhibiting different colors when viewed in different directions.
- noun The exhibition of essentially different colors by certain solutions in different degrees of dilution or concentration.
from the GNU version of the Collaborative International Dictionary of English.
- noun (Opt.) The property of presenting different colors by transmitted light, when viewed in two different directions, the colors being unlike in the direction of unlike or unequal axes.
from Wiktionary, Creative Commons Attribution/Share-Alike License.
- noun The property of some
crystalsof transmittingdifferent coloursof lightin different directions.
- noun physics The property of some
anisotropicmaterials of having different absorption coefficientsfor light polarizedin different directions; circular dichroism.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- noun pleochroism of a crystal so that it exhibits two different colors when viewed from two different directions
Sorry, no etymologies found.
He also studied the orientation of purines and pyrimidines in tobacco mosaic virus and in nucleic acids, by measuring the ultraviolet dichroism of oriented specimens, and he studied, with the visible-light polarizing microscope, the arrangement of virus particles in crystals of TMV and measured dry mass in cells with interference microscopes.
If now a stone that exhibits dichroism is held in front of the square hole and viewed toward the light, two images of the stone are seen, one due to its ordinary ray (which, as was said above, will have one color), and the other due to its extraordinary ray (which will have a different color or shade of color), thus the color of the two squares will be different.
Not all stones that are doubly refracting exhibit dichroism.
Also, owing to the dichroism of the ruby the red is variable according to the changing position of the stone.
Purple spodumene (kunzite) is pinkish to lilac in shade -- usually pale, unless in large masses, and it shows very marked dichroism.
Although strongly doubly refracting, the hyacinth shows scarcely any dichroism and thus lacks variety of color.
And as in some real rubies there are found slight hollows corresponding or analogous to the bubbles found in melted glass, it becomes a matter of great difficulty to distinguish the real from the imitation by such tests as hardness, specific gravity, dichroism, and the like, so that in such a case, short of risking the ruin of the stone, ordinary persons are unable to apply any convincing tests.
Almandine garnets also show no dichroism and lack variety of color.
This stone is doubly refracting, exhibiting extremely strong dichroism, especially in the blue and the green varieties.
The stronger dichroism of the tourmaline frequently reveals itself to the naked eye, and there is usually one direction or position in which the color of the stone is very inferior to its color in the opposite direction or position.