Friday, February 10, 2012

Chrysoprase, a Rare Quartz

Chrysoprase is a chalcedony, which is a form of silica that contains minute crystals and small quantities of a specific nickel compound, willemseite. It is a part of the quartz group and is distinguished by its apple green color which can vary to darker greens. The nickel compounds give it its color, and it has a hardness of 6 to 7, making it suitable for use as a gemstone. Chrysoprase is found in Australia, Germany, the Ural Mountains, the United States (California and Arizona), and Brazil. Polished chrysoprase can resemble turquoise or jade. It is the rarest stone of the chalcedony group.

Chrysoprase is used today in ornaments and jewelry of all types. Peter Carl Faberge incorporated chrysoprase in some of his most beautiful creations. Chrysoprase was used as a medicinal and spiritual therapy during the Middle Ages to reduce internal pain, strengthen vision, and increase dexterity. Spiritually, it was also used to as a mental health treatment and as an aid to increasing powers of concentration and meditation. Chrysoprase is also thought to calm the nerves, prevent depression, and increase fertility. Other health uses for chrysoprase include the breaking of negative life cycles, promoting inner growth, and inspiring hope. Chrysoprase is associated with the Gemini, Libra, and Taurus signs and the sacral, solar plexus, heart, and throat chakras. It has a numerology vibration of 3.

Thursday, February 2, 2012

Bauxite, the Aluminum Rock

Bauxite is an aluminum ore that contains the minerals gibbsite, boehmite, and diaspore; the iron oxides goethite and hematite; and the minerals anatase and kaolinite, which is a clay. There are two types of bauxite: silicate and carbonate. Silicates are found mostly in tropical areas and carbonates are found in Europe and Jamaica. The French geologist, Pierre Berthier discovered that bauxite contained aluminum in 1821 in Les Baux, France, after which the rock is named.

Bauxite ranges from white or gray to a dark red-brown, has a dull luster, and a hardness of 1-3, which makes it unsuitable for making beads or jewelry by itself. Because bauxite is usually found near the land surface, it is usually strip mined. Bauxite production is processed into alumina, and then into aluminum by electrolysis.

Aluminum is increasingly used in jewelry making and wire work because of its relative abundance and cheaper price. It comes in many colors and wire gauges and often anodized to make it resistant to corrosion and provides a surface for better adhesion of paint primers and glues. Aluminum wire is very soft at the same gauge as nickel or brass wire, so it is better to use a lower gauge when you want a piece of jewelry to hold its shape. Sixteen, twelve, ten, or nine-gauge aluminum wire is stiffer, but thicker than another wire of the same gauge. Aluminum charms are lightweight and ideal for jewelry making.

Many jewelry suppliers now carry aluminum jewelry making supplies. I am going to try the lower-gauged aluminum the next time I buy a bunch of supplies.

Wednesday, February 1, 2012

Little-Known Minerals

Ulexite is a mineral, also known as TV rock, that is mainly found in California, Nevada, Chile, and Kazakhstan.  Its scientific name is hydrated sodium calcium borate hydroxide. It is named after a German chemist G. L. Ulex, who discovered it in the 1800s.  Ulexite contains optical fibers that polarize light into slow and fast waves, which can transmit an image to the other side of a rock.  Internal reflection of the slow waves and the refraction of the fast waves cause a unique optical effect when held over an object.    

Since ulexite is a soft substance and dissolves in water, it cannot be used as a gem for jewelry making. It is also brittle and contains clay particles, which often hinder light transmission. It is white and sometimes lightly colored due to the clay impurities.  It often

Ulexite is white to lightly colored by impurities, commonly clay.  Its unique optical property is that is transmits light along the long axis of the crystal by internal reflections, very much in the same way as in fiber optics.  Clay particles often hinder this light transmission. Ulexite can alter to gypsum and colemanite.