Glossary |
||||||||||||||||||||||||||||
| ANTIQUING: | ||||||||||||||||||||||||||||
| Antiquing is essentially the process of artificially inducing the natural process of the tarnishing of metals. Depending on the plate type, parts are either darkened with chemical solutions or with specially formulated metal marking inks. Both approaches are carefully monitored to achieve a consistent appearance that creates polished highlights and dark, contrasting recessed areas. | ||||||||||||||||||||||||||||
| COPPER: | ||||||||||||||||||||||||||||
| Copper is believed to have been the first metal used by man. Today it is used extensively in all aspects of manufacture of nonferrous (metal with no iron content) products. In its pure state, it is a warm pinkish red color, easily worked, but subject to tarnish by simple exposure to air. Copper is usually the first layer in plating and then other metals being plated over it. TierraCast is delighted to now carry solid copper crimp beads, along with our popular head pins, eye pins and jumprings. | ||||||||||||||||||||||||||||
| COPYRIGHT: | ||||||||||||||||||||||||||||
| The Federal Government offers protection from illegal copying of artistic creations, including jewelry designs. The enforcement of Copyright Law to protect the creative output of company, ensure fair competition among consumers as to the origin and quality of the product. Tierracast is proud of both its design innovation and quality of product and will aggressively defend its rights under Copyright Law. | ||||||||||||||||||||||||||||
| GOLD: | ||||||||||||||||||||||||||||
| Gold is a precious metal that is very soft when pure (24kt.). Gold is alloyed (mixed with other metals, usually silver and copper) to make it harder and less expensive. The purity of gold is measured in karats. TierraCast also offers solid 14-karat ear wires. Solid 14k is 14 parts pure gold out of 24 and the remaining 10 are other metals. | ||||||||||||||||||||||||||||
| GOLD FILLED: | ||||||||||||||||||||||||||||
| Gold-filled products are a mechanical composition of thin karat gold layers and base metal cores. The use of heat and pressure applies the layer karat gold to the base. Gold-filled wire products are manufactured to federal standards, marked and sold accordingly. Our ear wires at TierraCast are 14/20 gold filled wire, which is an abbreviation for their gold content by weight. 14/20 gold filled wire is composed of a base metal (bronze) wire core and mechanically clad with a tube of 14k gold that is 1/20th (by weight) of the total weight. | ||||||||||||||||||||||||||||
| MEASUREMENTS: | ||||||||||||||||||||||||||||
There are several different measurement systems used in the jewelry trade.
* The common paper clip is approx .032" (B & S #20) |
||||||||||||||||||||||||||||
| MEASURING METAL CONTENT: | ||||||||||||||||||||||||||||
The most common way to refer to lead is by its percentage of total weight in the alloy and when discussing the higher levels, the use of simple percentage is useful. When discussing lead levels in metals below the 1% level however, it is more common to transform these percentage numbers into ppm (parts per million). This ppm approach is used by regulatory agencies and laboratories to express standards and report test results.
| ||||||||||||||||||||||||||||
| MSDS: | ||||||||||||||||||||||||||||
Tierracast pewter products do not require MSDS because they do not contain materials "that may create a hazardous exposure during their use" and, as such, also are exempt from the regulations of the Standards as they meet the definition of “articles” as outlined below. The following is a quote from Patricia K. Clark, Acting Director, formerly of the Directorate of Compliance Programs OSHA You may also wish to explore the info on MSDS at this URL: http://www.ilpi.com/msds/osha/index.html |
||||||||||||||||||||||||||||
| NIOBIUM: | ||||||||||||||||||||||||||||
| Niobium is an elemental metal which is strong yet flexible. Niobium is chemically non-reactive, therefore very hypoallergenic. It can be transformed into brilliant colors through the anodizing process. The colors do not negate the metal's hypoallergenic qualities. | ||||||||||||||||||||||||||||
| PEWTER: | ||||||||||||||||||||||||||||
| There is an increasing interest concerning the presence of lead in pewter alloys, and the potential health hazards of lead. We hope the information presented here will expand your understanding of the pewter used by TierraCast, as well as other alloys that are used in the jewelry trade.
The Federal Trade Commission and the American Pewter Guild define pewter as a "metal alloy product of which the chemical composition shall be not less than 90% Grade A Tin, with the remainder composed of metals appropriate for use in pewter." TierraCast uses an alloy called Britannia, composed of 92% Tin, 7½% Antimony and ½% Copper. Tin is refined from ore that contains other metals, including lead. A chemical process is used to remove the lead, but trace amounts still remain. Our casting alloy is routinely tested for lead content, yielding results ranging from 179 to 300 parts per million (PPM). This is well below the Food and Drug Administration's (FDA) standard of 500 PPM deemed safe for pewter used for culinary purposes in contact with food. Although all pewter contains trace amounts of lead, the term "lead free pewter" is sometimes used to describe pewter that meets the stringent FDA standard. Unfortunately, many jewelry components are made of metal containing substantial and sometimes alarming amounts of lead. Tests that we have run on other cast jewelry components yield lead contents as noted in the chart below.
Lead is commonly used in pewter alloys because it is easy to cast and very inexpensive, costing 1/8th as much as tin. However, lead is a known toxin that accumulates in the body causing numerous physical ailments. In recent decades, focus on this problem has resulted in the elimination of lead in gasoline and paint. Now there is increasing concern and discussion about lead content in metal alloys used in items that come in contact with people, particularly children. This has led to the recall of millions of metal jewelry items that were manufactured overseas. TierraCast takes the issues concerning lead very seriously and buys only pewter that is routinely tested to comply with stringent FDA limits (see article on the extremely low lead content of our alloy). This way, we protect our clients, ourselves and our environment from exposure to lead. We continue to research this issue and will share what we learn as more information becomes available. |
||||||||||||||||||||||||||||
| PLATING: | ||||||||||||||||||||||||||||
| The plating of our pewter findings is done by standard industry methods of depositing thin layers of various metals on the surface by immersing them in an electrolyte solution and passing an electrical current through them. While each plated part receives various layers, the final surface offered by TierraCast is one of four common types. Gold Plate of 22k quality is used on TierraCast parts. We use an 18k color and a medium luster finish on its cast parts. All gold plated thicknesses are above 10 millionths of an inch and thus qualify under the Federal Trade Commission terms of "Gold Electroplate." The plate thickness is sufficient to withstand reasonable wear and tear, but is not so thick as to resist aggressive cleaning or machine polishing. Any cleaning should be done with mild detergents and a soft cloth. Silver Plate is done using .999 Fine Silver as the final plated surface and has a thickness of at least of at least 20 millionths of an inch. Unlike gold, this plated metal surface is susceptible to tarnishing, even though they are sealed with a final anti-tarnish layer during manufacturing. Rhodium Plate is often used as a "silver colored" alternative to real silver plate. While more gray in color than silver, Rhodium is highly scratch resistant and does not tarnish. Copper Plate is applied in thickness sufficient to allow for chemical antiquing and machine relief to give the plated parts a natural antique look. |
||||||||||||||||||||||||||||
| PROPOSITION 65: | ||||||||||||||||||||||||||||
Tierracast, Inc cast pewter products do not require labeling with Prop 65 notices. The Proposition 65 regulations set Safe Harbor levels for exposure to a long list of chemicals, and adopted a range between .5 and 15 micrograms a day as the limit for lead. The .5 microgram limit is that most often cited, as it serves as the Safe Harbor level to prevent reproductive toxicity. Items containing levels above those values must be marked with a Prop 65 warning notice notifying potential buyers that the items contain lead in quantities that pose potential health risk. Recent independent laboratory tests report that TCI cast pewter components average 200 ppm of lead, with a tested exposure of only .382 micrograms/day. Both these values are markedly less than (1) the FDA standards for lead in pewter in contact with food (at 500 ppm), (2) the current Consumer Products Safety Commission policy that sets 600 ppm (.06%) of lead content and 175 micrograms/day exposure as the threshold of enforcement, (3) as well as the values established in a recent settlement of a lawsuit that paves the way for a California standard that echoes the CPSC policy of 600 ppm of lead. |
||||||||||||||||||||||||||||
| RHODIUM: | ||||||||||||||||||||||||||||
Rhodium (Rh) is one of the six metals in the "Platinum" group of noble or precious metals. It is rare, chemically stable and highly resistant to oxidation and corrosion. It is commonly plated on sterling silver neck chains to protect them from tarnishing. Rhodium is ideally suited for the jewelry industry. It is a sought after, long lasting and non-tarnishing finish. It’s brilliant gray-white color is compatible with sterling silver and silver plated products. |
||||||||||||||||||||||||||||
| SILVER: | ||||||||||||||||||||||||||||
| Fine Silver (marked .999) is the most pure form of silver commonly available, and is often alloyed with other metals (most notable copper) to form Sterling Silver. The appearance of both forms is less gray in color than nickel or rhodium, though both will tarnish with exposure to air. | ||||||||||||||||||||||||||||
| STERLING SILVER: | ||||||||||||||||||||||||||||
| Sterling is an alloy of 92.5% silver and 7.5% copper. The sterling alloy produces a metal that maintains the lustrous white color of silver while increasing the strength and durability. TierraCast wire products, ear wires and sterling coils, are made from sterling wire supplied by reputable domestic suppliers. | ||||||||||||||||||||||||||||
| TARNISH: | ||||||||||||||||||||||||||||
| When metals tarnish (discolor with grey, brown or black spots or streaks) a thin layer of the metal is actually combining with oxygen and other chemicals in the air or water to form oxides of the base metal. The most common tarnishing is caused by the simple contact with air. Sulfur and other natural elements are the cause. An extreme example can be seen if silver or copper jewelry is worn into a natural sulfur hot spring. Tarnish on plated silver parts is a result of having been plated with .999 fine silver, which forms a yellow-tan oxide. In comparison most Sterling silver forms a grey-blue oxide more commonly recognized. Protective coatings are often applied to metal parts in an attempt to inhibit this process. They can be more or less effective depending on how successfully they isolate the metal from contact with other substances, including contact with the skin. These coatings usually have a short life and are easily scratched or worn. | ||||||||||||||||||||||||||||