The Turquoise is universally recognised as a Venus stone, though sometimes erroneously attributed to the Zodiacal House of Capricorn, which is ruled by the planet Saturn. It responds to the vibrations of both Venus Houses, but seems strongest in Taurus.

This stone was, in ancient times, known as the Turkis, or Turkeystone, as most of the specimens found in Europe in those days came from Persia through the hands of Constantinople merchants. The best specimens still come from Persia, although Turquoises are also mined in Arizona, U.S.A.; in China and Thibet and Russia; and in the Crown Jewels of Spain are many Turquoises brought from New Mexico over two hundred years ago.

The Turquoise is more frequently used for Amulets than any other stone, as much for its mystic virtues as for its beauty, particularly in the East, where sentences from the Koran are engraved upon it and the characters gilded.

Amongst its many virtues it was believed to warn of poison by becoming moist and changing colour; and it is said that King John, by these indications, detected the poison that caused his death. This gem has always been regarded as a pledge of true affections, and is also credited with the power of drawing upon itself the evil that threatens its wearer; but this quality belongs only to the Turquoise that has been given, and not purchased. Bcetius de Boot tells of a stone that had been in the possession of a Spanish gentleman living near his father; the stone was of exceptional beauty, but at the time of its owner's death it had entirely lost its colour and was said to resemble Malachite more than Turquoise. Because of this de Boot's father bought it for a very small sum, but not liking to wear so shabby-looking a gem, he gave it to his son, saying, "Son, as the virtues of the Turkois are said to exist only when the stone has been received as a gift, I will try its efficacy by bestowing it upon thee." De Boot, although he did not much appreciate the gift, had his crest engraved upon it, but had not worn it a month before it regained its original beauty. Shortly after this the stone gave evidence of its power, for as de Boot was riding home in the dark his horse stumbled and fell from a bank to the road ten feet below, neither horse nor rider being any the worse for the fall; in the morning the stone was found to be split in two.

It is for qualities such as these that it is prized by the Turks as a horseman's Talisman, they believing that it makes a horse sure-footed and protects its rider from injury by falls; and Camillus Leonardus says: "So long as a rider hath the Turquoise with him his horse will never tire him and will preserve him from any accident, and defend him that carries it from untoward and evil casualties".

In the Middle Ages the Turquoise was believed to appease hatred, relieve and prevent headaches, and to change colour when its owner was in peril or ill-health. The change of colour must not be permanent, and the stone should recover its real hue when the illness or danger is passed.

A gentleman who is a practical business man, holding an important position in the City, to whom I supplied a Turquoise, assured me that on two occasions when he was in personal danger the stone paled, but afterwards recovered its natural colour. It is not, however, sensitive to the changes in his states of health.