Jewelry supplies

The mention of the word plastic caught the author s attention. It is well known that NIR has been used successfully for years to identify various plastics in a totally nondestructive manner. Why, then, not use it to differentiate plastic turquoise lookalikes from the real McCoy Accordingly, samples were solicited from local jewelry stores and jewelry supply houses. This wasn t any easy task. More than once I was immediately shown the front door when I asked for samples of fake turquoise. (The nerve of even suggesting that a jeweler might offer other than the genuine material ) But one sympathetic dealer and a local consultant/collecter eventually lent me a few stones. 

Early human civilizations used stone, bone, and wood for objects. Approximately ten thousand years ago, metals first appeared. The first metals used were those found in their native form, or in a pure, uncombined state. Most metals today are acquired from an ore containing the metal in combination with other elements such as oxygen. The existence of native metals is rare, and only a few metals exist in native form. Iron and nickel were available in limited supply from meteorites. The first metals utilized widely by humans were copper, silver, and gold. Pure nuggets of these metals were pounded, in a process known as cold hammering, with stones into various shapes used for weapons, jewelry, art, and various domestic implements. Eventually, smiths discovered if a metal was heated it could be shaped more easily. The heating process is known as annealing. Because the supply of native metals was limited, metal items symbolized wealth and status for those who possessed them. 

Except for its source of outside current, the electrolytic cell has the same elements as the electrochemical cell an anode and a cathode placed in an electrolyte in which cations (positive ions) move toward the cathode, and anions (negative ions) move toward the anode. The oxidation half reaction at the anode and the reduction half reaction at the cathode can be added together to find the overall redox reaction for the cell. The process is called electrolysis. If a coating of silver metal is desired on a piece of silver jewelry, electrolysis can be performed to coat or plate the silver jewelry in an electrolytic cell. The electrolyte silver nitrate (AgN03) solution supplies a source of silver ions (Ag+). The cathode is the silver jewelry, from which silver ions are reduced to silver metal. The anode... 

Another candidate for a useful material from very high pressure synthesis is the gem material, jadeite (NaAlSi206). The natural material of Imperial quality can cost as much as 2000 per carat. Jadeite can be synthesized at about 30 kb and above in equipment similar to that used for diamond growth, and it has been made into pieces of jewelry. Since jadeite is used as a poly-crystalline aggregate, synthesis is essentially hot pressing and sintering, much simpler than if single crystals were needed. However, it does not appear to be a commercial product in competition with the natural supply. 

In the 1870s the demand for ivory, which was harvested from the trunks of a rapidly dwindling supply of hapless elephants, was high and increasing. Ivory was a favorite of the rich and famous, who used it for items such as jewelry, piano keys, billiard balls, etc., and there was a desperate need to find new materials for some of these applications. Alexander Parkes, a prolific English inventor, and John Wesley Hyatt, a great American... 

Lack of a resource supply (e.g., crude oil for a refinery, natural gas for chemical feedstocks, a diamond mine for a jewelry operation). 

Automotive catalysts and jewelry are the two dominant markets for platinum (approximately 80%) and are important elements in the econometric model. The investment industry consumes a minor amount of material but can exert significant influence on short-term price. However, over long periods of time, investment should have zero impact on supply and demand. 

The two biggest demand sectors are jewelry and electronics. In 1997, 2360 tonnes (86%) were used for jewelry while 184 toimes (6.7%) were used for electronics. Dental materials used 2.4% of the total gold supply, 2750 tonnes, that year [5.6]. 

The Consumer Product Safety Improvement Act of 2008 (Public Law 110-314) increased the budget of the CPSC, imposed new testing and documentation requirements, and set new acceptable levels of several substances including lead. It imposes new requirements on manufacturers of apparel, shoes, personal care products, accessories and jewelry, home furnishings, bedding, toys, electronics and video games, books, school supplies, educational materials, and science kits. The act also increased fines and specifies jail time for some serious violations (Table 4.20). 

The bulk of supply from aboveground stocks comes from the recycling of the metal contained in manufactured (or fabricated) products, the vast majority of which comes from jewelry. It is therefore not surprising that the supply from recycling, typically referred to as old scrap, has generally kept to a rising trend, reflecting the addition each year to the pool of available metal from that year s jewelry production. 

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