Amethyst rare mineral specimens Crystals and precious gem

The Gemstone & Mineral Amethyst

PHYSICAL PROPERTIES:
VARIETY OF: Quartz , SiO 2 , Silicon Dioxide.
CRYSTAL SYSTEM: Trigonal
COLOR: various shades of lavender to deep purple
USES: Gemstone and ornamental stone.
REFRACTIVE INDEX : 1.544-1.553
HARDNESS: 7
CLASS: tectosilicate
CLEAVAGE: none
FRACTURE: conchoidal
LUSTER: vitreous
STREAK: white
PLEOCHROISM: weak to distinct
SPECIFIC GRAVITY: 2.65
TRANSPARENCY: opaque to transparent

DISTINGUISHING CHARACTERISTICS:
Amethyst is the purple variety of quartz and is one of the most popular gems. If it were not for its widespread availability, Amethyst would be very expensive. Amethyst is a widely used gem. Most Amethyst is faceted or cut into cabochons for jewelry. Large chunks of Amethyst are carved. Amethyst is also popular among mineral collectors.

The Color Of Amethyst, has become a coined phrase. Many things are said to be of an Amethyst color. Even other, more expensive purple gemstones are often compared to its color and beauty. It must always be purple to be amethyst. But it comes in a very wide range of purple shades. Amethyst comes in long six sided crystals or can form as druzies that are crystalline crusts that only show the pointed termination's. Its color and nice crystal shapes make it a popular mineral specimen.

Phantom quartz shapes are sometimes present in the interior of quartz crystals, outlining an earlier stage of the crystal's formation. These phantoms are usually composed of other minerals or other varieties of quartz This leaves a coating on most or all of the surfaces of the crystal during its growth. The crystal then resumes its crystallization creating a phantom crystal outline within itself. Some of the crystals we have show these phantoms.

LOCALITIES:
Long, well-shaped crystals come from two Mexican localities. Vera Cruz and Guerro. We have some of the Guerro verity. Vera Cruz has very pale, clear, prismatic crystals that are sometimes double terminated and have grown on a light colored host rock. These crystals are typically have phantoms, having a clear quartz interior and an amethyst exterior. Some have phantoms. Guerrero has dark purple, prismatic crystals that radiate outward from a common attachment point. Often the crystals have phantoms opposite of Vera Cruz amethyst having a purple interior with a clear or white quartz exterior. These crystals can be quite valuable.

Most other Amethyst is massive or stubby pyramidal drusy clusters. Large quantities of fine Amethyst come from Minas Gerais, Brazil. Most faceted material is from this locality. Also in Brazil is Rio Grande do Sul, Bahaia. Here it occurs with Agate. The crystals form in druzy crusts that line the inside of volcanic vugs. Some of the vugs can be quite large. The crystals that form are usually light to medium in color and only colored at the tops of the crystals. Most clusters form with gray, white and blue agate and have a green exterior on the vugs. Calcite sometimes is associated and inclusions of cacoxenite are common.

Another South American country, Uruguay. Produces crystals in large geodes and pipes. These crystals are dark to medium and form in druzy crusts that line the inside of the geodes and pipes. They have a gray or brown exterior. The crystals are usually colored throughout and form with an agate base that may contain bright colors like yellow, orange and even red on occasion. Often amethyst coated stalactites and other unusual formations occur inside these vugs.

Two notable Canadian occurrences are Thunder Bay, Ontario and Digby, Nova Scotia. Amethyst pebbles are found on the beaches along the Bay of Fundy. At Thunder Bay a distinct red hematite inclusion just below the surface of the crystals is unique to this locality.

Large amounts of Amethyst are found in Zambia and South Africa. These crystals are usually large but not attractive. However, the interior color and clarity are excellent and many finished
products such as beads and gemstones are made from them.

Some other interesting Amethysts have come from countries like Italy, which has large parallel growth clusters with good even color. Germany has colorful agates that form a light colored druzy crust and the Ural Mountains in Russia. Have a very clear and dark variety that is usually cut into expensive gemstones.

There are a great many locations in the United States. Most of these seem to have been too small or just plain not worked commercially. Maine had dark druzy clusters that are not widely distributed today. North Carolina has druzy clusters with a nice bluish-violet tint. Pennsylvania has druzy clusters that fill fractures in metamorphic rocks. They are generally a brownish purple and patchy in color. The Deer Hill, Maine and Pennoyer Mine at Redfeather Lakes, Larimer Co., Colorado. Have druzy clusters that form crusts inside of fissures in sandstone, often on top of a crust of green fluorite. Crystals are dark but rather small. Fine Amethyst crystals can be found at Four Peaks, in the Mazatzal Mountains, Gila Co., Arizona. Many Amethyst crystals are found in the pegmatite dikes in Jefferson Co., Montana. Very rare Amethyst scepters are found at Crystal Park near Dillon Montana. Amethyst is found in several areas of western North Carolina. In the early 1900's, excellent Amethyst clusters were found in Paterson, Passaic Co., New Jersey, but the area is now built over. We have Amethyst geodes from the location called Red Top, On Bluett Pass. Kittitas County, Washington. We have also seen Amethyst from all over the North West, including our native state of Idaho.

FACTS AND HISTORY:
Amethyst and citrine are both verities of Quartz. The difference is color. But natural citrine, with its lovely transparent yellow to orange color, is extremely rare. So almost all citrine on the market is actually amethyst that's been heated to change its color.

The name "amethyst" came from the Greek word "amethustos" which means "not drunken."
In the first century, Pliny wrote that amethyst was so named for its color being nearly the same as that of wine. Early Greeks believed that drinking wine from an amethyst cup would prevent intoxication.

Some say an old Greek mythology legend, may have been instrumental, in the naming of this gemstone. In this legend, the God, Dionysus is outraged by an insult. He Vows to set his tigers upon the first mortal to cross his path. A young girl on her way to the shrine of the Goddess Diana, comes upon the tigers. To protect her, Diana transforms her into ‘rock crystal’ (quartz). Afterwards the remorseful Dionysus pours a goblet of wine onto the crystal as an offering to the girl. This gives the crystal a purple hue.

The astrological signs of amethyst are Pisces, Virgo, Aquarius and Capricorn.
Amethyst is the symbolic gemstone for the 17th wedding anniversary.
Amethyst is the birthstone for the month of February

Click below for more Quartz Information:
The Quartz Family