Dragon hand-carved from Ruby in Zoisite. No less than 170 mm in size and 500 grams in weight.

The ruby (derived from the Latin ruber, "red") is a red gemstone, a variety of the mineral corundum in which the color is mainly caused by chromium. Natural rubies are exceptionally rare, while artificially produced ones are relatively cheap. In addition to the clear gemstone ruby, there is also the less clear semi-precious stone of the same name. This stone has been valued since ancient times. The oldest written sources on ruby mining mention quarries in Burma. From there the stones came via trade routes to the courts and temples of the ancient Egyptians and Greeks. In the Middle Ages, rubies were also popular in Rome. Initially they were worked into an oval shape. The very large and beautiful stones also have their own names. The ruby was considered the stone of life, which strengthens the heart and returns strength. In ancient times and the Middle Ages, rubies were attributed magical powers. The Bible also recognizes the value of the ruby, although in some of those passages the point is that there are treasures of greater value: wisdom is more precious than rubies (Proverbs 3:15) and the value of a good wife far exceeds that of rubies in the sight of her husband (Proverbs 31). Also in Job 28, ruby is mentioned as one of the treasures that man seeks in places where the priceless and untraceable wisdom of the living God cannot be found. It should be noted that what is sometimes identified as 'ruby' in the Statenvertaling appears under completely different names in some other translations. In this interpretation, one must take into account what was considered valuable in the culture and time at which the translation in question was prepared. Ruby also has a mythological meaning. The ruby is one of the "nine gemstones" in the Thai Order of the Nine Gemstones. Rubies are mined in Africa, Asia and Australia. They are most commonly found in Burma, Sri Lanka and Thailand, although they have also been found in Montana and South Carolina. Rubies have a hardness of 9 on the Mohs hardness scale, and among natural gemstones are only surpassed in hardness by diamonds. Other varieties of corundum are called sapphire. Ruby gemstones are valued according to several characteristics such as size, color, clarity and cut. All natural rubies have imperfections and only artificial rubies can be completely free of imperfections. The fewer the number and less obvious the imperfections, the more valuable the ruby is, unless there are no imperfections at all (i.e. a "perfect" ruby). In that case it could be that it is an artificial ruby. Some artificial rubies have substances added to them so that they can be identified as artificial, but most require the intervention of a specialist appraiser to determine the precise value.