Microwave Oven Produces Bright Red Rubies

The coveted rubies do not always have the desired red color. There, it can be done what about with chemicals or a laser. Indian scientists have now found a simpler and better way. They roast base stones in a microwave oven until they glow red.Gamma rays turn worthless Topazes that are the wrong color or are too pale, in precious blue stones. In rubies, not as desired shine in bright red, scientists have now discovered an easier way: It illuminates intensively with microwave ovens. The domestic microwave oven is suitable but unfortunately not to refine the stone.

So far, rubies, which had bluish bodies or were too dark, were treated with chemicals, irradiated with laser or heated strongly, to get the desired color.

Bright red Rubin after 50 minutes

The idea came from a woman: Subhashree Swain have developed the process by the Indian Institute for minerals and materials research in the East India Bhubaneswar and her colleagues. You were experimenting with reddish black rubies, which had been found in Sinapali in northeastern of India. For 50 minutes they put her in a microwave oven with a capacity of three megawatts, that is the performance of more than 3,000 microwaves in normal kitchens, who heated it to 1500 °C.

Oven Produces Bright Red Rubies
Made the ugly duckling into a beautiful Swan: a Ruby prior to treatment with microwave (li.) and then (re.). Photo: Subhashree Swain

The subsequent investigation, in which the researchers used X-ray diffraction as well as UV and Raman Spectroscopy, showed that the stones were so perfect, that even the most critical jeweler would have no objections. “The light absorbance at 560 nanometers has significantly increased, as the higher wavelengths ranging from 600 to 800 nanometers”, so Swain. This has resulted in that dark red and near infrared light is eliminated. The stones shine brighter.

The crystal lattice fixed itself

The heat shock, the Indian researchers, allows the molecules from which the crystal lattice is built, more freedom. You can resolve irregularities and defects in the crystal lattice. The heat also has an influence on the distribution of foreign atoms that are the root cause for the red coloring. Rubies are made of plain aluminium oxide, in which are foreign atoms have smuggled such as chromium, iron and titanium.

Red corundum as rubies are also called, are formed under extreme ambient conditions: at high pressure and high temperature prevailing in regions where two plates rub against each other, in the Himalayan region. In ten up 40 km depth, the mineral is formed of corundum, which is promoted in the course of many thousands of years to the surface there.

A Ruby Crystal was in the very first laser

“Heating in the microwave oven is an unconventional method for rapid thermal excitation,” says Swain. The treatment go faster than with other methods, and the crystal lattice will steady.

Rubies are used not only by the jewelry industry, but also by laser manufacturers. Theodore Harold Maiman began a Ruby in the world’s first laser in 1960, he built, which sent a laser beam as he was encouraged from the outside by xenon flash lamps

Red corundum are rubies.
Cut Ruby with Zoesit: A Ruby is the red variety of the mineral corundum. The mineral becomes red when it contains small amounts of chromium. Only the Red corundum are called rubies.