Amethyst, the most precious member of the quartz family, exhibits purple shades ranging from pale lilac to deep purple, sometimes exhibiting reddish or rose overtones. Very deep-colored amethysts are the finest and most highly valued. Some stones are so over-saturated with color they have areas that are blacked out, which can negatively impact their value. Paler shades, sometimes called "Rose of France," were common in Victorian jewelry. Banding—darker and lighter zones of color—is also a common occurrence. Occasionally, amethyst is even found combined with its sister quartz, citrine, into a single stone called ametrine.

The birthstone for February, amethyst is an extremely popular gem for jewelry because of its regal color, variety of sizes and shapes, affordability and wide range of hues. It also is the recommended gem for couples celebrating their 6th and 17th wedding anniversaries. With a hardness of 7.0 on the Mohs Scale , amethyst can occur as long prismatic crystals that have six-sided pyramids at either end, or can form as drusies that are crystalline crusts that only show the pointed terminations.

The ancient Greeks believed that amethyst made one immune to the effects of alcohol. In fact, the name even comes from the Greek word amethystos, which means “not drunken.” Legend has it that the amethyst originated from Bacchus, the god of wine. Bacchus became angry at the mortals and vowed that the next mortal to cross his path would be eaten by tigers. Amethyst, a beautiful young maiden, was on her way to worship the goddess, Diana. Diana turned her into colorless quartz to keep her from being eaten. Bacchus observed the miracle and repented his hasty decision. He poured wine over the young maiden, leaving her feet and legs colorless. This is the reason that amethyst crystals are usually uneven in color and have a colorless base at the bottom. Because amethyst was believed to prevent drunkenness, wine goblets were often carved from it in ancient Greece. Today, the gem still symbolizes sobriety.

Amethyst has been a part of history throughout the ages. Evidence suggests that prehistoric humans used amethysts for decoration as early as 25,000 B.C. Legends suggest that the Egyptian queen Cleopatra wore an amethyst signet ring, as did Saint Valentine, who bared an amethyst engraved with the figure of Cupid. During medieval times, people used the stone as medication to stay awake and alert. Leonardo Da Vinci claimed that amethyst could dissipate evil thoughts and quicken the intelligence. In some legends, the stone represents piety, celibacy and dignity. In the Middle Ages, for instance, the gem was an important ornamentation for the Catholic Church and other religions. It was considered the stone of bishops, and they still often wear amethyst rings. In Tibet, amethyst is considered sacred to Buddha and rosaries are often made from it. Amethyst has also long been a favorite of kings and queens for its royal purple hues that symbolize wisdom, strength and confidence. Amethysts are even featured in the British Crown Jewels and were worn by Catherine the Great.

Amethyst’s availability and magical qualities make it the stone of preference in ancient lore and mysticism. As a meditation stone, it is said to quiet the mind, promote contemplation, sharpen psychic powers and uplift the spirit. It is a stone of deep wisdom. Folklore says it can quicken the wit, calm fears, ward off anger and overcome alcoholism. It has a royal purple essence that is said to lend courage to travelers, scare off thieves and protect travelers from harm, sickness and danger. Placed under the pillow or worn to bed, there are claims it promotes peaceful sleep, pleasant dreams, and the healing of tired joints and muscles. Amethyst can also be worn to supposedly make the wearer gentle, amiable and happy.

The stone is mined in Brazil, Uruguay, Bolivia and Argentina, as well as in Zambia, Namibia and other African nations. Very dark amethyst in small sizes also is mined in Australia. But the ideal for fine quality amethyst was set by a Siberian variety, often called Russian or Uralian amethyst, which is now considered a defunct source. Generally, South American amethyst tends to come in larger sizes than African amethyst, but the African variety has a reputation for having deeper color intensity and is therefore considered more valuable. The African version also is harder to come by than amethyst mined from South America. Most of today's amethyst comes out of Brazil.

Onyx:

Onyx is a variety of chalcedony quartz that features a fine texture with a smooth black color. Some onyx can display white bands or ribbons against black or brown backgrounds. Mined in Brazil, India, California and Uruguay, most onyx today is color-enhanced to increase its depth of color. It ranks a 6.5 on the Mohs Scale and is an ideal stone for carving. In fact, it is a favorite material of lapidary artists.

Onyx was very popular with the ancient Greeks and Romans. The name comes from the Greek word “onux,” which means fingernail. Legend says that one day frisky Cupid cut the divine fingernails of Venus with an arrowhead while she was sleeping. He left the clippings scattered on the sand and the fates turned them into stone so that no part of her heavenly body would ever perish. In Greek times, almost all colors of chalcedony were called onyx. Later, the Romans narrowed the term to refer to only the black and dark brown colors, while the reddish brown and white onyx became known as sardonyx. Highly valued in Rome, sardonyx was especially used for seals because it was said to never stick to the wax. Roman General Publius Cornelius Scipio was famous for wearing sardonyx.

Worn during mourning in the Victorian age, onyx is now traditionally given as a 7th wedding anniversary gift. It is thought to increase happiness, intuition and instincts. The stone is also believed to cool the yearnings of love and decrease sexual desire.

Turquoise:

One of the oldest known gems, turquoise has been prized for thousands of years. The Egyptians believed it had powerful mystical properties, and turquoise jewelry has been found interred with 7,500-year-old mummies. Ancient manuscripts from Persia, India, Afghanistan and Arabia say that the health of a person wearing turquoise could be assessed by variations in the color of the stone. Montezuma’s treasure, now displayed in the British Museum, includes a carved serpent covered by a mosaic of turquoise.

Turquoise was especially revered by the Native American culture, an association that dates back to the Aztec empire more than 700 years ago. For the Aztecs, turquoise was reserved for the gods and mere mortals were forbidden to wear it. They believed it to be a gem of good fortune and a commodity more valuable than gold. Native Americans believed turquoise protected people from demons and they even placed turquoise in tombs to guard the dead. The stone’s colors were thought to be symbolically blue for the heavens and green for the earth. Often warriors tied turquoise to their bows to ensure accurate shots.

Today, turquoise is still believed to provide protection and bring luck. It is said to also promote prosperity, love, healing, courage and friendship. The stone is thought to relax the mind and ease mental tension.

The gem’s opaque turquoise color varies from shades of greenish blue to deep cobalt to sky blue. Some varieties display white or brown matrixes, which are streaks of the mother stone from which they came, while others have veins of color called “spiderwebs” running through them. Generally, the bluer the blue, the more highly valued the stone. A clear, even texture without mottling or veins is also preferred. The most rare and valuable color is an intense azure, but the most common is the mild to medium sky blue. Sometimes imitated by minerals such as chrysocolla, turquoise stones are often dyed or colored with coatings of various resins.

In the 13th century, turquoise was mistakenly believed to have come from the country of Turkey. Hence, its name came from the French word for Turkey, “Turquie.” The stone was actually brought to Europe from Persia (now Iran), via Turkey. It is a mineral usually found in association with copper deposits and is sometimes mined as a by-product of copper mining.

Although turquoise is found in desert regions worldwide, the finest and most valuable comes from Iran. Iranian turquoise is a pure robin’s egg blue that is free of green overtones, matrix or black veins. Perhaps the most famous turquoise today, however, comes from the southwestern United States. The occurrence in Arizona and New Mexico produces greener shades of the stone with matrix streaks of various colors.

While only ranking between 5.0 and 6.0 on the Mohs Scale of hardness, turquoise remains quite popular for jewelry. In Europe, turquoise rings are given as forget-me-not gifts, while in the United States, the stone is given as traditional 5th and 11th wedding anniversary gifts. It has even become a modern consideration for the December birthstone. When wearing turquoise over the years, the stone will absorb oil from a person’s skin, causing a slight change to the color of turquoise.