There are many fantastic materials used in the manufacture of jewelry today, but for the purposes of this article, I will concentrate on the big three: gold, silver, and platinum. In subsequent posts, we will discuss newer materials used in contemporary designs.
The Three Most Popular Metals in Jewelry; A Brief History
If we think about the precious metals (aka noble metals) used in jewelry today, they are really not that different from 4,000 B.C., when personal adornment with gold first began. And we’ve all seen pictures and studied ancient Egypt in school. The Pharaohs were draped in gold chains, drank from solid gold goblets, and wore chest plates of gleaming gold. Their gold jewelry and household items were so cherished that they were buried along with them in their tombs to use in the next life.
Silver too was also used for household items and objects of adornment. Beautiful high polished silver tea services and silver-handled hairbrushes, combs and mirrors were/are objects used by the elite upper classes. Although the craftsmanship and beauty of these items are unquestionable, there is little or no demand for them today. Everyone is familiar with the phrase, “born with a silver spoon in his (or her) mouth.” The phrase connotes wealth and privilege. Silver jewelry is considered a staple today and highly desirable by young people looking to start their jewelry wardrobes with a high-quality, beautiful precious metal; due to its inherent beauty and reasonable price points it is accessible to almost everyone.
The third most frequently used precious metal used in fine jewelry is platinum. But its use in the manufacturing of jewelry is relatively recent due to the fact that up until the late 1800s there was no torch that burned hot enough to melt platinum. The melting temperature is 1772 degrees Celsius (3215 degrees Fahrenheit.) But because of its strength and density, it can be crafted into delicate lattice designs. Its use was limited during War II, as platinum was needed for the war effort. This in turn led to the invention of white gold.
Precious Metals And Their Alloys
First, what is a precious metal alloy? and why wouldn’t 100% pure metals be used?
When mined from the earth, precious metals are separated from surrounding materials and are in their raw, or pure state. In order to craft jewelry or objects and be described as precious, they must be workable, in other words, malleable (ability to be hammered or pressed permanently out of shape without breaking or cracking) and ductile (ability to be drawn out into thin wire.) So how is this achieved? Precious metals are alloyed (mixed) with base metals.
The purpose of alloying
precious metals is to create a new metal with beneficial properties that no pure metal has on its own. For example, alloying will increase a metal’s hardness and make it more durable. “Karat” refers to the actual percentage of pure gold a piece contains, as compared to its alloying metals.
Gold: Of the three, gold is the most complicated of the metal alloys and can be confusing.
- Pure gold is described as 1000/1000, parts this is 24 karat. In its purest form gold is quite soft. It is used to make beautiful gold coins (mixed with other elements for strength) and gold bars. Bullion is a term is used to describe metals of very high purity. In countries such as India, 24 and 22 karat gold is used in the finest jewelry pieces, enough gold must be used so that they do not bend and offer adequate durability. Bullion and coins are stamped 999.9 and 24k jewelry. Stamped: 24k or 999.9.
- Next, is 22 karat which is roughly 92% pure gold 920/1000. Stamped 22k or 920. 80 parts copper, silver, zinc or nickel.
- 18 karat, which means 750/1000 or 75% gold and 250 parts other metals such as nickel, copper, silver, nickel, zinc or a mixture of these. Stamped: 18k or 750.
- 14 karat is roughly 58.5% gold or 585/1000. 415 parts copper, silver, nickel, zinc. Stamped: 14k or 585
- 10 karat is 41.7% or 417/1000 parts gold 10 parts gold and 583 base metals, such as nickel, zinc, and copper. Stamped: 10k or 417
- 8 Karat gold is occasionally found. 33.3% pure 333/1000 667 parts base metals. Those of us that grew up in the seventies might remember puzzle rings from Turkey, which were 8 karat and VERY difficult to reassemble when they came apart!! Stamped: 8k or 333.
Silver is a little more straightforward. Fine silver is .999 or 99.9% pure and is found in silver bars and some collectible coins.
Sterling silver is at least 92.5% 925/1000 pure silver by weight with 7.5% 75/1000 copper and sometimes nickel or palladium. Sterling is the most common silver we see in the marketplace. U. S. Federal Trade Commission (FTC) guidelines state that anything containing less than 92.5 percent silver cannot be called sterling silver. Stamped 925
Coin silver is .900 or 90% silver and 10% base metals. The name is derived from days gone by when old silver coins were melted down and the silver was used to make jewelry. This jewelry is rarely seen today, but if found, will have a quality mark, .900, and will no doubt be quite old.
Platinum as mentioned earlier is the youngest noble metal. It is rare to find platinum jewelry older than 100 years. Because of its hardness and strength diamonds in top-quality pieces are almost always set in platinum. Platinum’s exceptional density makes it heavy and strong and its white color will not reflect color into diamonds. The difficulty in mining and refining platinum adds to the value and cost of the metal, which is the most expensive of the three. Like gold, platinum is alloyed when used in jewelry, usually with other members of the platinum group such as iridium,
ruthenium. The most popular alloy is 95% platinum with 5% ruthenium. Because these metals are rare and valuable in their own right, they too add to the cost and value of platinum jewelry. You will immediately notice the heavier weight the moment you hold a piece of platinum jewelry in your hand. Stamped PT950 or Plat.
How Do Various Colors Of Gold Get Their Color?
Have you ever wondered, when shopping for gold jewelry, why the colors vary from store to store and even counter to counter? Well, that has to do with the “recipe” of the alloy. I mentioned earlier the various metals that are mixed in with the gold, the amount is based on what karat is being produced. The percentage of base metals added will always be the same depending on which karat gold is being produced, but the individual amounts that comprise that percentage can differ, which in turn can alter the color. But logically, the higher the karat, the more gold and the brighter yellow the piece will be.
Other popular colors are:
White Gold: Gold is naturally bright yellow in color. Therefore, even white gold is not completely white. 18k white gold consists of gold, copper, silver, nickel or palladium, and then plated in rhodium. Rhodium is a platinum group metal that gives the piece a brilliant, long-lasting, white surface color. Plating white gold with rhodium is a widespread practice in the industry.
Rose Gold: Rose gold is extremely popular due to its soft hues. Based on what you’ve read so far, can you guess how the pink color is achieved? It is copper, usually a higher amount in the “recipe” to achieve the desired hue. Higher or lower amounts of copper in the recipe produce red and pink gold respectively.
Black Gold: Is actually caused by surface treatments, such as oxidation, patination (that leaves a thin black surface coating) or vapor disposition (a heating and vacuum process that deposits a layer of dark rhodium on metal) all of which will eventually wear off, but the process is repeatable.
Advantages Of Precious Metals
Gold Alloys – Facts and Advantages:
- Variety of colors
- Wide range of price points based on the ratio of gold to base metals in the piece, and design (delicate or more hefty)
- Mixes and matches well with white metals
- Gold does not tarnish
- Yellow and rose gold can be polished to restore bright shine
- White and black gold require rhodium finish – no polishing required
Sterling Silver Facts and Advantages:
- The shine and brightness of the metal – 90% of light is reflected off its surface
- Attractive and accessible price-points
- Sterling silver jewelry is a great first-time jewelry purchase
- Many designs are mixed with gold and/or gemstones
- Sterling silver is 100% antibacterial, which is why baby cups, spoons and rattles are popular sterling silver gifts
Platinum Alloys – Facts and Advantages:
- Strongest and most dense of the precious metals
- Its strength lends itself well to delicate designs
- Platinum does not tarnish
- Platinum settings do not reflect yellow into near colorless and colorless diamonds
- Its strength lends itself to settings for high-quality diamonds and gemstones for extra security
- Ideal for customers with sensitive skin – 100% hypoallergenic (used in surgical instruments)
- Can be polished to restore the majority of its reflectively
- Mixes well with other white metals and all colors of gold
Caring For Your Precious Metal Jewelry
Sterling Silver: What are tarnish and patina?
Tarnish is defined as a surface discoloration of silver alloys caused by sulfur dioxide, a naturally
occurring element in the atmosphere, or by contact with sulfur-rich substances such as egg
yolks, rubber bands, or chemicals containing sulfur. The discoloration can be black, bluish-black
or even red to orange. It can be removed simply by polishing or dipping pieces in silver jewelry cleaner.
Patina is defined as a soft dull finish created on the surface of silver. A multitude of tiny scratches, caused by daily wear results in patina after prolonged wear. If you prefer a bright reflective surface, pieces can be re-polished to restore most of the shine. Some people prefer the softer, mellowed appearance that patina creates and do not want their pieces polished. If you are one of these people it is important to tell the jewelry professional you are working with, should your silver piece require repair. Use a liquid cleaner (such as the one sold in jewelry stores) for sterling silver items to remove tarnish, but not the patina. Rinse and dry well to avoid residual dark spots; if they do form they are very difficult to remove.
Gold and platinum do not tarnish and can be cleaned using a non-abrasive, clear liquid jewelry
cleaner or polishing cloth. Do not wear gold when in swimming pools. Chlorine will create small dents or holes on the surface of the metal. To restore the brilliant, shiny surfaces on all precious metal surfaces (other than rhodium plated items) professional polishing is required.
Store jewelry in the packaging provided at purchase– do not store unprotected in jewelry boxes or on hard surfaces, where harder materials, such as diamonds will scratch and damage other pieces.
All jewelry should be removed when using household chemical cleaners, as well as when playing sport.
In conclusion, precious metals used in jewelry, such as gold, silver and platinum create beautiful jewelry that if well taken care of will last and can be cherished for generations.
If you are interested in learning more about silver and gold, such as daily spot prices, or would like to purchase coins and bullion please visit 7k Metals for details. 7k Metals
Please feel free to leave a comment or ask a question below!
Francesca, G.G., F.G.A.