The diameter of the brooch: 44.6 millimeters. A very rare and valuable brooch model made of 916 silver, with high-quality Laboratory Rubies. Rubies are in good condition, glowing in ultraviolet light like a natural stone. Laboratory Ruby has all the properties of a natural stone: it is characterized by high hardness, strength and chemical resistance, it is resistant to scratching and wear. The brooch and stones are in good condition, it has no damage. The needle and latch are fully operational. It has a dark patina (natural oxidation of silver). Production of the Soviet Socialist Union in the 1970s. The owner of this brooch can confidently consider himself the owner of the “Purest ruby”, because only a gemologist using a microscope and studying the crystal lattice can distinguish a “natural ruby” from a “synthetic” one. Due to the fact that there were no natural deposits of precious rubies (red stones and their shades) on the territory of the Soviet Union, USSR scientists mastered the process of creating artificial corundums (rubies) completely identical to natural ones in laboratory conditions. According to the Verneuil method, an “artificial ruby” was created from aluminum oxide under the influence of ultrahigh temperatures (2500 degrees Celsius = 4500 Fahrenheit), completely identical to natural in all parameters and properties and significantly superior in purity. Artificially grown rubies (red) stones and their shadows are used in all jewelry of the Soviet Union made of silver and gold.