What gems are the most valuable? Seek help from the great god

Ruby refers to ruby-grade red corundum, and sapphire refers to any corundum except red. Only corundum crystals with a diameter of more than 5 mm and a weight of more than 0.6 carat are considered as gem-grade, and the value of high-quality large sapphires is second only to rubies, emeralds and diamonds of the same quality. The precious ruby variety is pigeon blood red, followed by bright red, pink, purple to deep purple; Sapphire is bright and pure in color, followed by dark blue, cyan, sky blue, light blue, gray blue and blue with gray, black, green and yellow. As long as the color is pure and bright, it is precious. The higher the transparency of rubies and sapphires, the better the quality. But besides star ruby and star sapphire. Starlight means that the stars in a gem can be seen with the naked eye, just like scattered starlight (best). But if the star line is thin and the length and angle of each star line are equal, then I suggest you not buy it. This is an artificial star gem. In other words, the star line of the natural starlight gem is irregular and deviates from the center of the gem. When buying rubies and sapphires, the seller must be required to issue a formal quality certificate. In addition, in the actual purchase of sapphire, the more transparent the better, the purity and purity of blue. Dark blue, dark blue is worse. The less impurities, the better. The purchase requirements of rubies are also comparable to those of sapphires. The quality of rubies and sapphires with a general market price of 1000 yuan is moderately low, and the quality of two or three thousand yuan is medium. Domestic jewelry companies offer different prices for rubies and sapphires. In addition, the Mohs hardness of emeralds is between 7.25 and 7.75 degrees, which means that natural emeralds can scratch the glass. If the emerald you bought can't leave scratches on the glass, it must be fake emerald. Emerald is bright green with high transparency. The gem can't be cracked again, and the crack shall not exceed 5% of the total volume. In other words, if there are obvious cracks inside the jade, it can be said that it is not the top grade. Emerald production is scarce, and at present, high-quality emeralds in domestic jewelry stores are rare. Also pay attention to distinguish between sapphire and aquamarine. Although there is only one word difference between them, they are different in nature. If the merchant does not clearly mark sapphire and aquamarine when selling gems, it is recommended that you do not buy them in this store. Aquamarine is a kind of beryl, but its value is far less than emerald. The jewel necklace worn by Ruth in the famous Titanic is aquamarine. Opal is also one of the five precious stones (diamond, ruby, sapphire, emerald and opal), but there are almost no pure top-grade opals in China at present, and top-grade natural opals are of great value.