Metals play a critical role in the creation of contemporary jewelry by affecting appearance, durability and cost. With such a dramatic impact, it's important that anyone interested in wearing or purchasing jewelry develop a basic understanding of the metallurgy as it relates to jewelry. In an effort to give you a sound foundation, let's review the basics of metals in jewelry making that include a brief history of metals in jewelry making, a review of the types of metals used in today's jewelry and conclude with a glossary to familiarize you with terms that you may encounter during your search for the perfect ring, bracelet, necklace or other item.
Metals are as old as human civilization and their history in jewelry making can be traced back thousands of years. As early as 6000 BC, metals were used by ancient peoples like the Mesopotamians, Egyptians, Greeks and Romans for a variety of uses, only one of which was jewelry making. The source of the term "metal" is unknown, but it's widely regarded that it could have come from either a combination of the Greek words metallin ("to search after) and metallon ("mine" or "metal"), or the Latin word metallum ("mine" or "metal"). Over time, jewelry making continued to evolve as new metals were discovered starting with Gold (6000 BC) and continuing with Copper (4200 BC) and Silver (4000 BC).
Generally speaking, there are several ways in which metal can be classified and it's helpful to understand the differences. These include Ferrous vs. Non-Ferrous, Base vs. Noble and Precious vs. Non-Precious metals. Let briefly look at each:
A Ferrous metal is one that contains Iron, while a non-ferrous metal does not. Since these forms of metals tend to rust, most jewelry is created with non-ferrous metals. Normally, most jewelry is made from non-ferrous metals with the exception of steel jewelry.
The terms Base and Noble as applied to metals refer to the chemistry of metal. Base metals are relatively abundant and tend to oxidize or corrode relatively easily; some examples include iron, nickel, copper and titanium. Noble metals, on the other hand, are rare, possess a high surface luster and are resistant to corrosion. Examples of Nobel metals include gold, silver and platinum. Understandably, most jewelry is made with Noble metals.
The difference between Precious and Non-Precious metals is primarily one of rarity and value. Precious metals include Gold, Silver and the Platinum family while Non-Precious metals include all others. In addition to having a higher value, Precious metals are particularly desirable for jewelry because they are less reactive than most elements, possess a higher luster and are easier to work with.
Today jewelry is created using a wide range of material, however the number of metals that can be used is limited; there are only 86 known metals and of those, relatively few are commonly used in contemporary jewelry. However, the majority of jewelry crafted today tends to use only a handful of metals. Here, we'll look at the metals that are the most popular.
Perhaps no other substance on earth has captured the hearts and minds of man more than gold. Popular for its rarity and luster, gold quickly became a method of payment and a key component used in the manufacture of jewelry when it became fashionable during the times of Alexander the Great. After a temporary decrease in status, gold regained its popularity as a jewelry staple often seen used in gold rings during the 15th century and continues to be popular today. Gold is the most easily worked of all metals and ranges in softness based on its purity. Generally pure gold is too soft for use in jewelry, so it's commonly mixed with alloy metals such as copper and zinc. Below is a breakdown of the percentage of pure gold in each of the popular karat weights:
24 Karat: 99.9% Pure
22 Karat: 91.7% Pure
18 Karat: 75% Pure
14 Karat: 58.3% Pure
12 Karat: 50% Pure
10 Karat: 41.7% Pure
When selecting jewelry like gold necklaces or bracelets, it's important to balance gold purity with the durability. Jewelry items like rings and bracelets often take more abuse and are much likely to become deformed if softer gold is used; as a result, 18 Kt or 14 Kt Gold may be a better selection for those types of items. In addition, there are a number of other forms of gold that must be considered when shopping for jewelry. They include:
Gold Vermeil Jewelry uses sterling silver which has been gold plated. The highest quality Gold Vermeil is 24K, but it can be made with varying qualities. For those considering a piece of Gold Vermeil jewelry it's wise to look for a Karatage label.
Gold-Filled Jewelry employs a process in which gold is bonded to a base metal alloy such as nickel or brass. Commonly, the amount of gold used must make up at least 5% of the total weight and all exterior portions are solid gold. Most gold-filled jewelry pieces tend to be 18Kt, but every piece of Gold-Filled jewelry should be labeled with its Karatage.
Gold Plated Jewelry employs a base metal which is then electroplated with gold. Usually a steel or brass item dipped into a bath of electroplating solution that deposits a thin layer of gold on the jewelry. The gold layer is less than gold filled, quite thin and will wear off faster than gold-filled.
White Gold Jewelry combines pure gold with other white metals, such as zinc, nickel, platinum and silver. Durable and resistant to tarnish, White Gold jewelry is brittle and requires platinum or rhodium plating. Generally produced to be a more cost effective than platinum, White Gold can cause allergic reactions once the plating wears off.
Rose Gold is an alloy that combines gold with copper to create a golden metal with a reddish hue. While it normally uses a gold to copper ratio of 3:1, rose gold can be found with varying percentages of each. Based on the addition of copper, the intensity of rose gold will be lighter or darker and will patina over time.
Silver has been used by man in jewelry nearly as long as gold. Mentioned in the Christian Bible's book of Genesis, Silver is also one of the only jewelry metals that's permitted to be worn by men of the Islamic faith, since the Prophet Muhammad wore a silver ring. Mention of Silver also appears in Greek mythology, where both Apollo and his twin sister Artemis carried silver bowls they had been given at birth. Clearly, the creation and use of Silver jewelry has an ancient tradition.
Like Gold, pure Silver is very soft and easily damaged, so it's commonly mixed with other metals to improve durability for use in jewelry. Silver is normally mixed with Copper and there are several levels of purity that indicate the quantity of pure Silver contained in the metal. For example, Sterling Silver must contain at least 92.5% pure Silver, however it's also found in varying purity levels including 958 and 999 Sterling Silver. Those interested in Silver jewelry should be able to determine the quality of the Silver used by looking for a stamp that indicates the metal's purity level.
With a variety of purity levels and uses, there are a number of different types of silver jewelry. Here are just several:
Fine Silver has a .999 level of purity, so it's also known as pure Silver. While particularly lustrous, Fine Silver is normally not appropriate for jewelry that's worn regularly, because it's not durable and bends easily.
Sterling Silver jewelry is an alloy that contains a mixture of 92.5% pure Silver and 7.5% of another metal, usually Copper. In order to be called Sterling Silver, the metal must possess at least 92.5% pure Silver, but the other components can vary. When mixed with copper, Sterling Silver will tarnish and may firescale. Regardless, Sterling is considered a standard among Silver grades and provides strength to ensure that pieces like silver bracelets, rings and necklaces can withstand regular use.
Silver Plate is a thin layer of Fine Silver placed over a base metal. Also known as Silver Tone, Silver Plate is often considered the most cost effective alternative to the more expensive forms of solid silver jewelry. That said, this form of silver is very thin, wears off easily and degrades in appearance quickly.
Nickel Silver is actually not silver at all! Despite its name, Nickel Silver is an alloy that combines Copper, Nickel and Zinc and contains no Pure Silver.
As one of the precious metals, Silver is among the most popular metals for the creation of jewelry. While there are many possible reasons for this preference, most people cite the following reasons:
Platinum is a silvery, white metal that's extremely rare and considered more precious than gold. Priced significantly above Gold, Platinum is among the heavier metals used in jewelry. Despite this increase in cost, platinum jewelry has become increasingly popular especially in platinum engagement rings and wedding rings.
Like most other metals used in jewelry, Platinum has an interesting history. Naturally occurring platinum and platinum-rich alloys were first used by ancient Egyptians, however it was not identified as an element until the 18th century. Spanish silver miners first named the metal "platina" or "little silver" when they first encountered it in Colombia, South America. Eventually, the Spaniards dismissed platinum as an 'undesirable impurity' in their mined silver, and often discarded it as a worthless by-product. Needless to say, that has changed today.
As with other metals, Platinum is commonly mixed with other metals. However, for a piece of jewelry to be labeled as "platinum" it must have a minimum level of purity of at least 95% pure platinum. A purity level of less than 95% would require the metal be identified as a Platinum alloy. Normally, Platinum jewelry pieces can be identified by a stamp with "PLAT"; a different stamp for the Platinum alloy would be "IRIDPLAT".
Stainless steel jewelry has become increasingly popular in recent years due to changing tastes and style trends that lean toward a more industrial look. Commonly used in a variety of industrial applications, Stainless Steel has found its way to fashion where it's used in everything from necklaces to earrings. Invented by Harry Brearley of the Brown & Firth Research Laboratories in 1913, Stainless Steel was developed to be impervious to staining or corrosion and was adopted by heavy industry.
Today, Stainless Steel jewelry is a favorite of both men and women that want an industrial, street look with a touch of flash. Departing from tradition, Stainless Steel jewelry can be found in the use of machined pendants, dog tags and more experimental pieces of jewelry.
Although the majority of jewelry is created using more popular and main-stream materials, there is still a diversity of metals that continue to be used to create some truly unique pieces of jewelry. Here we'll take a brief look at several:
Palladium is a rare Silver-white metal of the Platinum family.
Rhodium is a rare Silver-white metal of the Platinum family. It is particularly hard and is the most expensive precious metal.
Titanium is a natural element which has a Silver-white color. Titanium is the hardest natural metal in the world. It's three times the strength of steel and much stronger than gold, silver and platinum but yet is very light weight. Pure titanium is also 100% hypoallergenic which means that it if safe for anyone to wear.
Tungsten is a steel-gray metal whose strength and high melting point makes it a favorite of the arms industry. Metallic tungsten is harder than gold alloys and is hypoallergenic, making it useful for rings that will resist scratching, especially in designs with a brushed finish.
Copper is a reddish gold metal that patinas to a warm brown but can also take on a green patina with oxidation. The oldest known metal, it was associated with the Greek goddess Aphrodite and her Roman counterpart, Venus. In addition, Copper jewelry is often considered to have healing properties.
Brass is a copper and zinc alloy that's gold color. It will tarnish and turn brown overtime
Nickel is a white metal that looks like silver but can cause allergic reactions in some.
Annealing - Multi-phased heat and stress treatment that alters the microstructure of a metal adding strength, pliability, and hardness.
Adamantine - Refers to the light reflecting properties of a metallic surface, known as metallic luster.
Base Metal - Base metal is a term used to refer to a metal that oxidizes or corrodes relatively easily as with copper, iron, nickel, lead and zinc.
Carat - The term "Carat", "Karat" or "k" is used to indicate the amount of pure (24k) gold in the alloy. Lower Carat ratings indicate proportionally less pure gold.
Corrosion - Corrosion indicates the deterioration of a metallic material due to its reaction and subsequent oxidation due to a chemical reaction with water and/or oxygen.
Ductile, Ductility - A physical quality ascribed to a metal that will permit plastic elongation (wire drawing) without fracturing.
Firescale - Also known as "firestain," a red or purple discoloration that appears at high temperatures when oxygen mixes with the copper to form cuprous oxide, and then cupric oxide.
Forging - Heating a metal to a temperature where the metal becomes malleable (red hot) or deforming its shape by compression or exertion of force (hammering or cold forging).
Goldsmith - A goldsmith is a metalworker who specializes in working with precious metals to create jewelry.
Ingot - An ingot is a mass of metal heated past its melting point and then cast into the shape of a bar or block.
Luster - From the Latin word "lux", meaning "light". Describes the way light interacts with the surface of a mineral or metal.
Malleable - A physical quality ascribed to a metal that can be compressed, deformed, extruded, hammered, and rolled.
Mohs Scale - Created, in 1812, by the German mineralogist Friedrich Mohs, the Mohs' scale of hardness quantifies the scratch resistance of minerals by comparing the ability of a harder material to scratch a softer material ranging from Talc (1) to Diamond (10).
Noble Metal - Noble metals are highly resistant to corrosion or oxidation and include gold, silver, platinum, tantalum, and rhodium.
Oxidation - Oxidation removes electrons from a metal, and is thus reduces its mass. Oxidation (Redox) reactions include all chemical processes in which atoms have their oxidation number (oxidation state) changed.
Periodic Table - The periodic table of chemical elements is a tabular method used to classify, systematize and compare all the 116 (94 natural, 22 synthetic) basic chemical elements.
Plastic, Plasticity - A physical quality ascribed to a metal that can be bent and worked without rupturing. A non-brittle metal.
Smelting - A form of extractive metallurgy used to produce a metal from its basic ore components.