Wednesday, March 28, 2012

Ammonites

Ammonites are fossils of underwater predators that lived from 400 to 65 million years ago. The first animal to be classified as an ammanoid was the Goniatite from the Devonian Period 400 million years ago; the Ceratites came into existence during the Triassic Period 250 million years ago, and what most people refer to as ammonites developed during the Jurassic Period roughly 145 million years ago. All three types of ammanoids are sold as jewelry, individual fossils, and showpieces that are desired by collectors for their prehistoric appearance and for their beauty.

Goniatites are the earliest known predecessors of ammonites; they are small, ranging in diameter from 2 to 6 inches. One popular form of jewelry for all ammonites is the polished pendant, and goniatites are no exception. Their small size makes them ideal for wearing in pendants and necklaces, although they are desired by collectors in loose fossil form as well as embedded in rock slabs for showpieces. Goniatites can be found in Europe, North America, Australasia, and North Africa in areas that would have been subtropical during the time of the ammanoids' lifetimes.
Ceratites are a rarer form of ammonoid and are collected primarily as sculptures or individual fossils. Most ceratites are found in Germany due to the fact that the area was covered in water during the lifetime of this ammonite predecessor. Known for their four-lobed chambers, ceratites make a good addition to an ammonoid collection.
Ammonites are the most advanced form of ammonoid and are the most sought-after ammonoid from a collectible standpoint. These make excellent pendants and necklaces, especially when sawed down the middle and polished to showcase the ammonite's beautiful chambers. Ammonites are deposited in North America, Europe, Asia, and other places that were under the sea during the Jurassic and Cretaceous periods. They reached larger sizes than their ancestors, sometimes achieving 2 feet in diameter. Such large ammonite specimens are sought-after collectibles, as are smaller ammonites still caught in either a block of stone or stone that has been formed into a sculpture.
One of the most desirable forms of ammonite is ammolite, a high-quality gemstone formed from the shells of ammonite. Ammolite can only be found in the Rocky Mountains of North America, and the vast majority of all ammolite comes from Korite International out of Alberta, Canada. A few small private companies also mine a small amount of ammolite, along with small amounts of surface finds around the Rockies. Ammolite is collected in jewelry form in necklaces, rings, and other forms of jewelry as well as in rarer shell form. The beautiful stained-glass patterns present in full-shell form make full shells desired by ammonite collectors.
Touchstone Gallery of Arizona and New Mexico has a wide variety of ammonites and ammolites for sale. These stunning loose and stone-mounted ammonites and ammolites would make a fine addition to any ammonite or fossil collection.  www.touchstone-gallery.net

Sunday, March 18, 2012

Arizona Petrified Wood

Vertically Sliced Petrified Wood
     
                Horizontally Sliced Petrified Wood               


Arizona Petrified Wood – started as ancient wooden logs which have been preserved for millions of years because all the organic materials were replaced by quartz.
Over 200 million years ago, these large conifer logs were buried quickly and deeply by massive amounts of sediment.  The petrifaction process began when the wood was buried under that sediment, which delayed natural decay processes due to a lack of oxygen.
Mineral-laden water then flowed through the sediment, depositing numerous forms of quartz crystals in the plant's cells…….. and as the plant's tissues slowly decayed away, a near perfect stone crystal mold formed in the tissues’ place. Petrified wood can preserve the original structure of the wood in exquisite detail, including microscopic level tissues. Such details as tree rings and cell tissues can be observed in many specimens.
Petrified wood found in Northern Arizona is made up of nearly solid quartz. Each piece is like a giant semiprecious crystal, aglow with the natural sparkle of clear quartz, purple amethyst, red jasper, lavender chalcedony, yellow citrine, dark smoky quartz and solid black onyx.   The rainbow of colors that Arizona petrified wood is famous for is produced by minor impurities in the quartz. Typical examples include:
carbon - black                    cobalt - green/blue                
chromium - green/blue       copper - green/blue   
iron oxides - red, brown, and yellow manganese - pink/orange  
manganese oxides - black/yellow
Most of the petrified trees found in Arizona come from an ancient species known as Araucarioxylon arizonicum. Woodworthia and Schilderia are two other petrified genera also found  although in the area....... although much less frequently due to their rarity.
Petrified wood is the official fossil of the state of Arizona, provincial stone of Alberta and is also the state gem of Washington.
Cut and polished petrified wood can make a dramatic and interesting contribution to the décor of an office or home.  A very small group of artisans, who specialize in handling this extremely hard substance, transform the raw logs and chunks found on private ranches into tabletops, small-to-large polished slabs and slices, bookends and freeform table and mantle pieces.  Each piece brings with it both stunning beauty and a fascinating story that bridges the most recent 225 million years of Arizona’s history.  Perhaps you could imagine a 20 or 30 inch slice of semiprecious gemstone with a wonderful story hanging on a wall near you.
touchstone gallery offers a nice variety of these remarkable pieces and we invite you to visit any of our four locations to view our amazing selection of petrified wood décor……… or stop by electronically and view a small selection of our offerings at www.touchstonegalleries.com. 

Wednesday, March 7, 2012

The Natural Beauty Of Amber

Many people think of the 1990s blockbuster Jurassic Park when they hear the word "amber," but this lovely gem's appeal reaches much farther back than the 90s. Amber jewelry has been traced back as far as the Stone Age and the ancient Greeks thought amber was formed by the sun. Found predominantly near the Baltic Sea and the Dominican Republic, amber comes in several different colors and is sold in several different forms.

Amber comes in shades of white, yellow, red, green, blue, and black, and those who produce and appreciate it are almost as diverse. Amber is fossilized tree resin (not sap), which has been appreciated for its color and natural beauty since Neolithic times. Amber is used as an ingredient in perfumes, as a healing agent in folk medicine, sold raw, in slabs, in polished specimens, and as jewelry.
While some of it washes up on shore or in seaweed, much of it is mined from the so-called "blue earth" of Kaliningrad Oblast. Baltic Amber is used to make bracelets, broaches, necklaces, earrings, and other pieces of jewelry. Some of the Jurassic Park-style trapped organism specimens are found in Baltic Amber, but the majority are found in a less mature version of fossilized tree resin known as copal and in Dominican Amber.

The Ancients established what they referred to as the "Amber Road," an amber trade route that ran from Europe to Asia and back. This figurative road transported the finest Baltic Amber to eager Greeks and Romans. Today, Baltic Amber is still the most widely used amber for jewelry because of its fine coloring and its high level of succinic acid (from which Baltic Amber derives its Latin name of succinite).
Dominican Amber is clearer than most Baltic Amber specimens and is thus best for viewing trapped organisms and other traces of organic matter. There are some truly outstanding examples of insects and even the rare vertebrate entrapped in Dominican Amber that can quite often sell for more than the average piece of Baltic Amber jewelry. Dominican Amber can be used for jewelry as well, although its pure, clear color is not usually as highly desired as is the more opaque Baltic Amber. It is often mined by the dangerous method of bell pitting which leads to high on-the-job risk.

The rarest type of amber is Blue Amber, which is a type of Dominican Amber. In order to see this amber as blue, the light must hit it a certain way. For this reason, Blue Amber is often sold in a rough, natural form. Other types of amber can be sold in the rough form as well either for the appeal of the roughness or of the ability to shape the rough amber into a design of the owner's choosing.
Chiapas Amber comes from Mexico and is not as readily available as Baltic or Dominican Amber. Known for its purity of color and relative youth, it makes beautiful amber jewelry when available.
Touchstone Gallery of Arizona and New Mexico has a wide selection of beautiful amber jewelry for sale. These bracelets, rings, earrings and amber necklaces are made of high-quality Baltic Amber.  These pieces exemplify their company purpose, which states, "We love and sell minerals, fossils and jewelry! We offer amazing merchandise at fair prices in a unique and fun atmosphere." Each of the four Touchstone Gallery locations can be contacted by anyone who is interested in one of their pieces, with contact details available on the website www.touchstonegalleries.com . Touchstone Gallery has locations in Sedona, Scottsdale, Taos and Sante Fe and ships anywhere in the world.