Gold:
Gold has long been one of the most precious metals on the globe, and it is the most commonly used material for engagement rings and high-value jewelry.
When choosing gold, it is important to consider the look you want. Gold can come in many colors, the most common of which being, yellow, white and rose, but it can also come in blue, green and many other colors when alloyed with certain metals. The intensity of the gold color in yellow gold will also appear different depending on the karat.
Karat:
Gold is a very soft metal and most of the time, jewelry made from pure gold is very soft and delicate. In order to increase the durability and strength, decrease the cost and adjust the color, gold is commonly alloyed with other metals when used in jewelry.
- 10 karat gold – 41.7% pure gold (417 parts per thousand)
- 14 karat gold – 58.5% pure gold (585 parts per thousand)
- 18 karat gold – 75% pure gold (750 parts per thousand)
- 22 karat gold – 91.6% pure gold (916 parts per thousand)
- 24 karat gold – 100% pure gold
Common Alloys in Colored Gold:
- Yellow Gold – Copper and Zinc
- White Gold – Zinc, Nickel, Silver, Palladium (once the color has been dulled, the piece is coated in a layer of rhodium to give it a strong luster)
- Rose Gold – Copper gives rose gold its red/pink undertone
- Green Gold – Silver and Cadmium will give gold a green tint
- Grey Gold – Silver, Manganese and Copper, in precise ratios
- Purple Gold (Amethyst Gold or Violet Gold) – Aluminum; purple gold is the most brittle of the gold alloys
- Blue Gold – Indium or Ruthenium, Rhodium and three other elements (combined with a heat treatment)
- Black Gold – There are many ways of producing black gold, including alloying with Chromium or Cobalt and controlling the oxidation process
Platinum:
Platinum is a very dense white metal which has been used for centuries due to it’s color and durability. It is typically used in close to it’s purest form, the most common concentration of platinum being 90% (900 parts per thousand). When jewelry is made with less than 90% platinum, the exact proportions (in terms of parts per thousand) must be stamped on the inside of the piece. Platinum is most commonly alloyed with rhodium or cobalt.
Due to it’s durability, platinum is the most commonly used white metal in engagement rings, when it is an affordable option.
Platinum is also naturally hypoallergenic, making it a very popular white metal option for someone with a gold allergy.
Silver:
Silver is another metal which has long been considered precious to human beings. It is the best conductor of electricity of all known metals, and, when polished and maintained, it is one of the shiniest white metals used in jewelry. Most silver jewelry then undergoes a process called, flashing, in which it is plated with a thin coat of fine (100% pure) silver to give it a bright, shiny finish.
Most Common Types of Silver:
The most common form of silver used in jewelry is sterling silver, which is an alloy containing 92.5% (925 parts per thousand) silver. It is commonly alloyed with copper, making it more durable and easier to work with by giving it a harder texture and a lower melting point.
Britannia silver is an alternate form of silver containing 95.8% (958 parts per thousand) silver. It is most commonly used to make table and flatware.
Coin silver is another common alloy of silver containing 80% (800 parts per thousand) silver. It is most commonly found in coins and table/flatware.
Vermeil and Gold Filled:
The terms vermeil and gold filled are used to refer to a piece which is made from sterling silver or a base metal and coated in a thin layer of gold. These pieces are very affordable, but very difficult to work on and maintain. Gold filled or vermeil items could remain gold for up to 30 years (depending on the thickness of the layer of gold), but it will inevitably fade over time with enough wear.
In order for a piece to be considered “gold filled”, the plating must make up at least 1/20 of the total metal weight. In order to be considered “vermeil”, the coating must be at least 2.5 microns thick.
Palladium:
Palladium is a member of the platinum family of metals and shares similar qualities in terms of color and durability. Like platinum, palladium is hypoallergenic and often at least 90% pure when used in jewelry. Palladium is noticeably lighter in weight than platinum, and it was commonly used as a platinum substitute when the metal was needed for the war effort during WWI and WWII.
Rhodium:
Rhodium is a naturally white metal, which is also a member of the platinum family. It is the material most commonly used to coat a piece of white gold in order to give it a bright luster. Rhodium eventually wears off of every piece, and it is recommended that a piece of jewelry be rhodium plated every 12 to 18 months. It is not uncommon for people in fields involving the use of chemicals (such as a nurse or hairdresser) to have their pieces rhodium plated much more frequently.
Tungsten:
Tungsten is a very strong and durable metal, which is also very resistant to scratches. It has a permanent polish, meaning that the finish should hold firm without ever needing to be repolished. The most common alloy of tungsten includes 80% tungsten and 20% carbon.
It is important to recognize that rings made from tungsten cannot be resized, cut or soldered in any way.
Cobalt Steel:
Cobalt steel is a unique metal in that it is harder than platinum, while being less dense at the same time. It’s hardness makes it very resistant to scratches, while its density makes it malleable and easy to shape. Cobalt steel is another hypoallergenic metal, making it an attractive option for people with a gold allergy.
Stainless Steel:
Stainless steel is commonly used for architecture and appliances, but it is becoming more popular in jewelry, partially thanks to the work of designers who are turning to stainless steel as a cheap alternative to sterling silver.
Stainless steel is also commonly used in watches and body jewelry.
Titanium:
Titanium is a very inexpensive light-weight option for durable pieces of jewelry.
Aside from not being able to be sized, a titanium ring is also incapable of being cut off of a finger. This means that if an accident caused the ring to become bent or distorted in shape, it would be very difficult, if not impossible to safely remove. We highly recommend against the use of titanium in jewelry.