| Smoky (Smokey) Quartz is a common, | | | | gamma-rays, the color will occur again. Certain |
| coarse-grained variety of the silica mineral Quartz. | | | | smoky quartz is sensitive to ultraviolet light, it will |
| Its abudance causes it to be worth considerably | | | | turn pale if exposed to sunlight for a long time, |
| less than citrine or amethyst. The color of | | | | but it is not as sensitive as amethyst. At certain |
| smokey quartz ranges from nearly black through | | | | locations smoky quartz shows zones of yellow or |
| smoky brown. There is no distinct boundary | | | | violet color along with smoky ones. These |
| exists between smoky and colorless Quartz. | | | | different colors might be found in different layers |
| Irradiation and traces of aluminum built into its | | | | as phantoms. |
| crystal lattice are what give the smoky quartz its | | | | Smoky quartz is dichroic and when turned around |
| color, but sometimes it is believed that it is the | | | | an a-axis in polarized light, it shows a change of |
| high energy cosmic radiation which causes its | | | | color from red-brown to yellow-brown. It's still |
| coloration and not the radiation from radioactive | | | | common practice to artificially irradiate colorless |
| sources. Smoky (Smokey) Quartz is a common, | | | | quartz, it is then sold as smoky quartz. People |
| coarse-grained variety of the silica mineral Quartz. | | | | wont be able to tell just by looking at the crystal |
| Its abudance causes it to be worth considerably | | | | whether the source of the irradiation was natural |
| less than citrine or amethyst. The color of | | | | or not, but dealers are obliged to clearly label that |
| smokey quartz ranges from nearly black through | | | | quartz accordingly although some of them |
| smoky brown. There is no distinct boundary | | | | don’t do that and get away with it. |
| exists between smoky and colorless Quartz. | | | | Usually smokey quartz is found in intrusive igneous |
| Irradiation and traces of aluminum built into its | | | | and high grade metamorphic rocks, as these |
| crystal lattice are what give the smoky quartz its | | | | contain traces of radioactive elements. Smoky |
| color, but sometimes it is believed that it is the | | | | quartz from volcanic rocks is more uncommon, |
| high energy cosmic radiation which causes its | | | | here colorless quartz and amethyst dominate. |
| coloration and not the radiation from radioactive | | | | Smoky quartz from sedimentary rocks is unusual |
| sources. | | | | because their content of radioactive elements is |
| Typically, the color of smoky quartz is much | | | | usually very low. Many smoky quartz |
| more homogeneous than that of amethyst. | | | | reported from sedimentary rocks is actually not |
| Quartz with deep colored or almost black, usually | | | | really smoky quartz, but quartz containing brown |
| only occurs in igneous rocks. When heated to | | | | or black inclusions. Usually gangue quartz found at |
| about 200°C, true smoky quartz will loose its | | | | ore deposits is colorless or only slightly brown. |
| color and when the crystal is irradiated with x- or | | | | |
