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Showing posts with label Black Agate. Show all posts
Showing posts with label Black Agate. Show all posts

Wednesday, July 20, 2011

SOUTHWESTERN FLAIR - A Modern Look !

Keeping with the classic materials used in jewelry from the Southwestern United States, it can still be made to have a more modern look.






A pear shapped Turquoise Bead dangles as a pendant from this 20 inch necklace. Ivoryite barrels and Turquoise oval beads provide the bold dynamic look while black Agate (Onyx) chips are interspirsed between more Turquoise oval beads. All are highlighted with silver beads and the necklace is finished with a Hook Clasp.






Turquoise is an opaque, blue-to-green mineral that is a hydrous phosphate of copper and aluminium. It is rare and valuable in its finer grades and has been prized as a gemstone and ornamental stone for thousands of years owing to its unique hue. In recent times Turquoise, like most other opaque gems, has been devalued by the introduction of treatments, imitations, and synthetics onto the gemstone marketplace. The substance has been known by many names, but the word Turquoise was derived around the 16th century from the French language 'turquie', for a Central Asian material which was a very early imported through Turkey from Persia. Today, Persian and certain southwestern United States Turquoise, especially Sleeping Beauty, commend some of the highest prices paid for this gemstone. Many times on the edges of the Turquoise fields, other minerals and stones become interwined into the Turquoise or Turquoise pieces are encapsulated into the surrounding rock, thus creating unique and interesting patterns.







Ivoryite is a great substitute for ivory. It is a sedimentary precipitate of magnesium, calcium and silica. It is 5 to 5-1/2 on the Moh's scale, which makes it slightly harder than ivory. Ivoryite can be worked with metal tools, but cuts effortlessly with diamond tools. Polishes well with diamond, tin oxide, cerium oxide or white rouge. Excellent material for inlay, cabochons and small carvings. Do not confuse Ivoryite with Ivorite, whic is a black tektite material from Africa. The majority of Ivoryite currenly comes from the western United States, especially Colorado and California.







Black Agate (Onyx) which is truely a died black Agate, is more common and perhaps the most famous variety, but not as common as natural Onyx. Onyx is a crypyocrystalline form of Quartz. The colors of its bands range from white to almost every color (save some shades, such as purple or blue). A picture of a true Black Onyx specimum is seen below. True specimens of Onyx contain bands of colors of white, tan, and brown. As stated, the pure black form which most people know as Onyx, is not a naturally occuring variety. Black Agate or poorly colored Onyx is heated and dyed black to come up with the pure black form so well liked within the jewelry industry.






Matching Turquoise oval dangle Leverback Earrings complete the set.

Wednesday, July 13, 2011

ONYX or BLACK AGATE ?


Black Agate (Onyx) which is truely a died black Agate, is more common and perhaps the most famous variety, but not as common as natural Onyx. Onyx is a crypyocrystalline form of Quartz. The colors of its bands range from white to almost every color (save some shades, such as purple or blue). A picture of a true Black Onyx specimum is seen below. True specimens of Onyx contain bands of colors of white, tan, and brown. As stated, the pure black form which most people know as Onyx, is not a naturally occuring variety. Black Agate or poorly colored Onyx is heated and dyed black to come up with the pure black form so well liked within the jewelry industry.


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Striped Onyx is a cryptocrystalline form of Quartz. Striped Onyx is a redundant statement since true Onyx will have color bands that range from white to almost every color (save some shades, such as purple or blue). Commonly, specimens of Onyx that are seen in the market place contain bands of colors of white, tan, and brown. Pure black Onyx is actually Dyed Agate or poor grades of Onyx where the stripes, as seen below, have been dyed to black.




Agate is a microcrystalline variety of quartz, chiefly Chalcedony, characterised by its fineness of grain and brightness of color. Although agates may be found in various kinds of rock, they are classically associated with volcanic rocks but can be common in certain metamorphic rocks. White Agate or probably better known as Greek Agate, is a name given to pale white to tan colored Agate originally found in Sicily back to 400 B.C. The Greeks used it for making jewelry and beads. Today almost any agate of this white color is called Greek agate. Yet the stone had been around centuries before that and was known to both the Sumerians and the Egyptians, who used the gem for decoration and religious ceremony. True White Greek Agate comes only from Sicily, once a Greek Colony.



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Tuesday, September 14, 2010

GEMSTONE JEWELRY - Basic Black and White !

Sometimees the return to basics becomes a great idea, likewise returning to basic black and white in jewelry can be called a real "Return to Basics".
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In this "return to basics" design, two old gemstones are also used. White Agate, sometimes called Greek Agate, flat nuggets are combines with two sizes of Black Agate (Onyx) round beads and pewter accents with silver plated hammered chain and a lobster clasp to complete the necklace. Matching Black Agate (Onyx) round beads and pewter accents on French Hook earrings complete the set.
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Black Agate (Onyx) which is truely a died black Agate, is more common and perhaps the most famous variety, but not as common as natural Onyx. Onyx is a crypyocrystalline form of Quartz. The colors of its bands range from white to almost every color (save some shades, such as purple or blue). A picture of a true Black Onyx specimum is seen at the left. True specimens of Onyx contain bands of colors of white, tan, and brown. As stated, the pure black form which most people know as Onyx, is not a naturally occuring variety. Black Agate or poorly colored Onyx is heated and dyed black to come up with the pure black form so well liked within the jewelry industry.
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Agate is a microcrystalline variety of quartz, chiefly Chalcedony, characterised by its fineness of grain and brightness of color. Although agates may be found in various kinds of rock, they are classically associated with volcanic rocks but can be common in certain metamorphic rocks. White Agate or probably better known as Greek agate, is a name given to pale white to tan colored Agate originally found in Sicily back to 400 B.C. The Greeks used it for making jewelry and beads. Today almost any agate of this white color is called Greek agate. Yet the stone had been around centuries before that and was known to both the Sumerians and the Egyptians, who used the gem for decoration and religious ceremony. True White Greek Agate comes only from Sicily, once a Greek Colony.
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Pewter is a metaln alloy, traditionally between 85 and 99 percent tinn, with the remainder consisting of 1-4 percent copper, acting as a hardener, with the addition of lead for the lower grades of pewter and a bluish tint. Traditionally, there were three grades of pewter: fine, for eatingware, with 96-99 percent tin, and 1-4 percent copper; trifle, also for eating and drinking utensils but duller in appearance, with 92 percent tin, 1-6 percent copper, and up to 4 percent lead; and lay or ley metal, not for eating or drinking utensils, which could contain up to 15 percent lead. Modern pewter mixes the tin with copper, antimony and/or bismuth as opposed to lead. Physically, pewter is a bright, shiny metal that is very similar in appearance to silver. Like silver, pewter will also oxidize to a dull gray over time if left untreated. Pewter is a very malleable alloy, being soft enough to work with hand tools, and it also takes good impressions from punches or presses. Because of this inherent softness and malleability, however, pewter cannot be used to make tools itself. Some types of pewter pieces, such as candlesticks, would be turned on a metal lathe. Pieces produced through this technique are sometimes referred to as "holloware." Pewter has a low melting point of around 225-240°C (437-464°F) depending on the exact mixture of metals. Duplication by casting will give excellent results especially in jewelry making. Pewter is many times the base metal for Silver or Gold plating.
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Saturday, August 28, 2010

GEMSTONE JEWELRY - Amber & Turquoise !

Initially the Indians of the Southwest used shells, spiny oyster and some corals to add color to their Turquoise, Magnesite and Agate jewelry. From time to time traders would provide them with Amber, which was quickly incorporated into designs.
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This design incorporates Baltic Amber and stabilized Arizona Turquoise chips with a turquoise colored Howlite tear drop pendant and Black Agate (Onyx) barrels with a silver toggle clasp. Matching French Hook Amber and Turquoise chip earrings complete the set.
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To help understand the types of Turquoise on today's market. the following is provided----
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Natural - This comes directly from the mine. It is cut shaped and polished and set into jewelry. It has no man made treatment or additives other than a polishing compound that adds to its luster. Several pieces of natural Turquoise from Arizona, can be seen to the right and are beautiful with very little polishing. Most stones in this state are very close to gem quality. The coloration of natural Turquoise can darken as oils from the skin work its way into the stone over the years, especially of not properly cleaned.
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Stabilized – This is a natural turquoise usually in nugget form, but does not hold a luster. It is submerged into a stabilizing compound and dried, cut and prepared for jewelry. The turquoise has not been altered. The pores of the stone have been filled with a clear resin that makes the stone usable. This process allows for diversity of shapes and possibilities in jewelry making. Color Stabilized stones are considered altered and sometimes color has been added in this process. This in not necessarily bad, but it has less value than a piece that is naturally colored. Stabilized Turquoise usually does not change color with wear and because of its hardness, wears better in jewelry.
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Treated - This form of color enhancement has been used for thousands of years. It is done as discussed earlier by submerging Turquoise stones into animal fat or vegetable oil and later air dried. Normally the color will not last very long. A new variety on the market, called "Motaska" and "Majave" Stone is much more stable and retains its color as well as being infused with gold, silver and copper.
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Fake and Synthetic – Ceramics, bone, celluloid and plastic are used to imitate turquoise. Synthetic turquoise has a very natural matrix that is produced by placing stones in the synthetic “batter”.
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Imatations - Then there are the imatations, in many cases natural gemstones that are beautiful in their own right, but due to the fact they accept dyes, many times are dyed the various turquoise colors and then are sold by unscrupulous dealers as real Turquoise. Price becomes the real determining factor when it comes to seperating real Turquoise from dyed Howlite, Magnesite or Ivoryite.
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Black Agate (Onyx) which is truely a died black Agate, is more common and perhaps the most famous variety, but not as common as natural Onyx. Onyx is a crypyocrystalline form of Quartz. The colors of its bands range from white to almost every color (save some shades, such as purple or blue). A picture of a true Black Onyx specimum is seen at the left. True specimens of Onyx contain bands of colors of white, tan, and brown. As stated, the pure black form which most people know as Onyx, is not a naturally occuring variety. Black Agate or poorly colored Onyx is heated and dyed black to come up with the pure black form so well liked within the jewelry industry.
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Amber - The Baltic region is home to the largest known deposit of Amber, called Baltic amber, with about 80% of the world's known amber found there. It dates back some 44 million years ago. It has been estimated that these forests created over 105 tons of amber. Because Baltic amber contains about 8% succinic acid, it is also termed succinite. It was thought since the 1850s that the resin that became Amber was produced by the tree Pinites succinifer, but research in the 1980's came to the conclusion that the resin originates from several species. Numerous extinct genera and species of plants and animals have been discovered and scientifically described from inclusions in Baltic Amber. Do NOT confuse Amber with Copal. Copal is not the fossilized, but rather an immature recent resin. Increasingly, Copal is being offered for sale, via the online auction services, gem shows, and shops, misrepresented as "Amber." The commercial value of Amber is related to its scarcity, age, inclusions of extinct species, and durability. Unfortunately, some dealers are more preoccupied with high economic returns, rather than whether or not their resin is fossil or recent. The age of Copal can vary from 50 years to 1.6 million years in age. It can be considered a semi-fossilized resin or an immature amber.
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Howlite, named for its discoverer Henry How, who found it in Tick Canyon, California in 1868. Howlite is one of those minerals that is more famous for imitating another mineral than being used for itself. In most cases the other mineral is Turquoise, a phosphate gemstone. Although natural Howlite is always white or gray, it can accept dyes fairly easily and be dyed a turquoise blue. The look of turquoise is so good that dishonest dealers have been unfortunately successful at this hoax. In more honest circumstances, dyed howlite is an affordable substitute for turquoise carvings, beads, polished stones and cabochons. It accepts a nice polish and its porcelaneous luster is attractive and enhances even undyed beads and carvings. Unfortunately it has low hardness, but it still has a distinct toughness. California is the source for most all of the howlite trade where nodules of up to one hundred pounds have been found. In addition to the famous turquoise colored Howlite is dyed, it also can become a very bright red color to mimic red coral, or any other color in the rainbow.
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