The color of a stone

If you look at the jewelry store window in a jewelry store, you can be amazed at the brightness and variety of the color of the precious stone. The color of a stone fascinates... What pure and sparkling blood red rubies, azure blue lazuli, bright yellow topaz and green emeralds! The color of the stone is sometimes so remarkable that even in antiquity, the bright precious stone, called him the flower of the earth and attributed to him a special power and influence on man.

If you look at the jewelry store window in a jewelry store, you can be amazed at the brightness and variety of the color of the precious stone. The color of a stone fascinates

It turns out that the color of the same stone can be different. For example, beryl: dark green to deep blue-green aquamarine, golden yellow beryl, densely emerald and completely clean, colorless stones of the same beryl.

Take, for example, tourmaline. The color of this stone at one end may differ from the other. If you cut it along, it will be layered in a variety of colors: pink, green, blue, brown and black. In addition, some minerals change their color, if you look through them in different directions. This, the so-called, pleochroism. If you look through such a mineral, rotating it in your hands, then the color of the stone will change. However, there are topazes that appear blue on one side, and on the other side they are wine-yellow. The color of the whole stone does not change, but the color is so distributed that it seems to us that it has changed. Sometimes the coloring in the stones can be misdirected; if you take, for example, the Ural amethyst, a beautiful purple stone, and put it in a glass of water, then the coloring will immediately gather in one place, and the entire stone will appear colorless.

Some minerals change color in the evening light. Alexandrite, for example, is dark green in the daytime, but with the light of a lamp or a simple match it glows with a dark crimson color, and in the rays of the sun it seems gently purple with a bluish-green tint.

The color of the stone represents one of the most interesting, but at the same time, the most difficult tasks of modern mineralogy. So, it is still unknown exactly what determines, for example, the violet color of amethyst or the beautiful smoky color of golden topaz. True, we know that the red color of the ruby and the green color of the emerald depend on the admixture of the chromium metal, the color turquoise - from copper, and red agate - from iron. Sometimes the color of the stone does not depend on impurities at all, but is the result of the laws of the structure of the stone itself, the distribution of individual atoms and molecules in it. Such, for example, is the blue lapis lazuli.

But do not think that the color of the stone is always something permanent and unchangeable - it can be changed and artificially. In old Indian legends it was said that the stone is bright and beautiful only in the first time after it was removed from the earth, but then it fades, and its coloring, especially under the influence of the sun's rays, turns pale. It turns out that gems in the light often fade, emeralds and topaz brightens, and wine-yellow phenacite for only one month becomes colorless and pure, like water.

But even more remarkable is hackmanite! When it is broken in place with a hammer, the color of the stone is first cherry-crimson: it does not take ten to twenty seconds for a stone in the eyes to lose all its beauty and become gray. It is curious that if you hold this mineral in a dark place, then a few months later it returns to its beautiful color for a second.

The color of the stone can be changed artificially. For example, cornelian is often dirty-brown, but after calcination in fire it acquires a beautiful red color. This property was used by the Greeks and Romans two thousand years ago. So, they cooked agates for several weeks in a copper with honey, then washed with clean water and again boiled for several hours in sulfuric acid; from this turned out beautiful black with stripes stones - onyx. Smoky topaz in the Urals local peasants have long been baked in bread. In this case, the stone evenly heats on all sides and gradually changes its color. Just bake the amethyst, turning them into dark golden stones. Now these methods have become common, and there are almost no items made of unpainted natural stone: its coloring is always intensified by different methods.

Now scientists have learned more advanced ways to change the colors of the stone: they act on it with rays radium or special ultraviolet rays of a quartz lamp. It turns out that these rays can greatly change the color, giving the stone a beautiful shade.