In the dazzling world of jewelry, rubies, sapphires and emeralds are known as the “world's three most precious stones” by virtue of their unique charm. They are not only symbols of luxury and beauty, but also contain a wealth of scientific mysteries and fascinating qualities.
Ruby, known for its flame-like red color, and the most prestigious “pigeon's blood red” is the finest of all rubies. This fascinating red color is due to the presence of the element chromium. Geologically, chromium atoms replace aluminum atoms in the crystal structure of corundum, causing the crystals to absorb bluish-green light, thus giving them a vivid and intense red color. In terms of color grades, pigeon's blood red rubies are extremely saturated, emitting an intense red glow in natural light, as if a never-ending flame were burning inside. Its clarity, natural rubies often exist some inclusions, such as needle-like rutile inclusions, etc. These inclusions are not only an important basis for identifying natural rubies, in the right arrangement, but also produces a unique star effect, adding a different charm to the ruby. The hardness of ruby reaches 9 on the Mohs scale, second only to diamonds, which makes it relatively resistant to scratches and abrasions during daily wear and maintains its brilliance for a long time.
Sapphires come in a wide range of colors, including pink, yellow, green and purple, in addition to the classic blue, each with its own unique flavor. Blue sapphires are mainly formed by the combined action of iron and titanium, with different ratios of elemental content resulting in a variety of shades from light blue to deep blue. Cornflower blue sapphire, so named because its color is as elegant and charming as that of the German national flower, the cornflower, has a soft velvety texture, which seems to be covered with a layer of mist when exposed to the light, this unique visual effect stems from the light scattering effect of tiny filamentary inclusions inside the stone. Pink sapphires, with their sweet, soft colors, like cherry blossoms blooming in spring, have become very popular with women in the jewelry market in recent years. Yellow sapphires are warm and bright, giving them a sense of vitality and hope. Sapphires also have a hardness of 9 on the Mohs scale, and their good physical properties make them an excellent material for all types of jewelry.
Emeralds, which have captured the hearts of countless people with their rich, deep green color, derive their green color from the elements chromium and vanadium. Unlike rubies and sapphires, emeralds are usually rich in inclusions within them, which are imaginatively referred to as “gardens” because they look like miniature plants, rivers and clouds intertwined. These inclusions affect the clarity of the emerald, but they also become its natural signature, and each emerald's “garden” is unique. The hardness of emeralds is 7.5 - 8 on the hardness scale, which is relatively low compared to rubies and sapphires, and their brittle nature makes them susceptible to fissures during mining and processing, which makes high-quality, large-carat emeralds extremely rare and precious.
In jewelry appraisal, professionals use a variety of instruments and methods to examine the characteristics of these stones. For example, a refractometer is used to measure the refractive index of gemstones, which is usually in the range of 1.76 - 1.78 for rubies and sapphires, and 1.57 - 1.59 for emeralds; a microscope is used to observe the characteristics of inclusions within the gemstones to determine their origin and naturalness; and a spectrometer is used to analyze the type and content of chromogenic elements in the gemstones, to further ascertain the quality and value of the gemstones. The quality and value of gemstones can be further determined by analyzing the type and content of color-causing elements in gemstones through spectroscopy.
Understanding the basic characteristics of rubies, sapphires and emeralds not only allows us to better appreciate the beauty of these gems, but also helps us to make informed decisions when shopping for jewelry. Whether it is the passionate ruby, the elegant sapphire or the mysterious emerald, each gemstone carries a unique charm and story, waiting to meet its match.