Metals

Platinum

A white metal with a deep luster and a rich, white color, Platinum is used in jewellery in almost its pure form (approximately 95% pure). Although a soft metal, platinum is not easily scratched and is very strong and durable. The strongest precious metal used in jewelry, platinum also has a high melting point and good resistance to corrosion and chemical attack. Minimal amounts of iridium and ruthenium are commonly added to it, to give it a harder, stronger alloy that retains the advantages of pure platinum.  At kestanejewellery.com we still rhodium plate all out platinum pieces to give it a brilliant white finish.

A very dense and heavy metal, a platinum ring will feel heavier (approximately 60%) than an 18kt gold ring.

 

Platinum is usually marked with the following symbols: PL, PT, PLAT, 950 or PT950.

Platinum is, however, significantly more expensive than gold. A platinum ring will most definitely cost more than the price of an 18kt white gold ring, with all other things being considered equal.

Often used to set the most valuable gems to produce the finest jewelry, Platinum is one of the most popular metals of choice for ring settings, because the strength and color of platinum enhances the brilliance and depth of diamonds and precious stones.

Considering platinum is the purest metal, it rarely causes an allergic reaction. Worldwide there is an increased interest in platinum jewellery commonly in ladies and men’s wedding rings, earrings as well as pendants.

Gold

A chemical element that has amazing physical characteristics, gold is extremely well suited for use in jewelry making. Although gold is the most malleable of all metals, gold is so durable that it is virtually indestructible and does not corrode. Gold can be re-melted and used again to create new designs.

Gold remains as the most popular choice for wedding rings and engagement rings, and is equally popular in dress rings, earrings, pendants, necklaces and bracelets.

There are two primary considerations when looking at gold. First; which gold karat to choose and second, the gold color or the combination of gold colors that are available.

Gold karat

10k, 14K, and 18K and in some cultures 22K are the variety of available gold karats.

Karat represents the gold content of the metal. The karat measures the proportion of pure gold mixed with other metal alloy to make up the final metal.

The karat of gold is represented in many countries by the abbreviation ‘K’ or ‘Kt’.

You may notice that carat or ‘ct’ is also used to measure the weight of diamonds and gemstones. Although the same name is used, the two measurements are measuring different characteristics of jewellery. In addition the measurement for gold uses a ‘k’ for ‘karat’ as opposed to the ‘c’ in ‘carat’ for diamonds.

The higher the proportion of gold used in the final metal, the more valuable and expensive the metal becomes. All other things being considered equal, an 18kt ring will be more expensive than a 14kt ring, and a 14kt ring will be more expensive than a 10kt ring.

 

10kt gold contains 41.7% pure gold (417 parts pure gold per thousand parts)

14kt gold contains 58.5% pure gold (585 parts per thousand parts).

18kt gold contains 75% pure gold (750 parts per thousand parts).

The remainder of the metals is made up of a combination of alloys, different metals which can help to give the metal its unique appearance, such as a different color.

Jewelry is normally stamped with a marking to show the type of gold.

For 10kt gold the stamp will normally be either the number 417 or 10K.

For 14kt gold the stamp will normally be either the number 585 or 14K.

For 18kt gold the stamp will normally be either the number 750 or 18K.

 

The karat stamp only indicates the karat of metal. It provides no indication as to the color of the metal. For example an 18kt yellow gold ring would have a stamp of 750 as would an 18kt white gold ring.

Suitable for use in all types of fine jewellery, 10kt, 14kt and 18kt gold are each relatively hard. When choosing jewellery, particularly rings, many people consider the hardness and durability of gold to be used in their ring.

The Vickers scale is what is used to measure metal hardness. Therefore, harder metals receive a higher Vickers score than less hard metals.

Gold colors

Your next consideration is in the color of the gold.

Available in several different colors the most popular is yellow gold, followed by white gold and rose gold, though other gold colors are sometimes also available such as bronze, red and lime gold.

A combination of different gold colors can also be used to make jewellery. These jewelry items are sometimes called two-tone, three-tone or multi-colored gold.

The gold content of yellow gold and for example white gold is measured in the same way. For example an 18kt white gold ring contains 75% pure gold and 18kt yellow gold contains 75% pure gold as well.

The use of metal alloy mix is what differentiates color between yellow, white and rose.

As the color difference is due to the metal components in the alloy mix, the color of yellow gold and rose gold will not chip, fade or wear off with age.

Yellow gold is made by mixing pure gold with alloy metals such as copper and zinc.

Rose gold is made using a mix of pure gold with alloys including copper. The copper provides the rose-reddish color.

White Gold

 

White gold is an alloy of gold and some white metals such as silver and palladium.

Nickel used to be the primary choice of alloy mix for white gold, however most white gold today no longer uses nickel as it can cause reactions with some people. We at kestanejewellery.com do not use nickel in our white gold.

When white gold rings are new they can be coated with another white metal called Rhodium. Similar to platinum, rhodium also shares many of the properties of platinum including its white color.

Rhodium plating is used to make the white gold look whiter, because the natural color of white gold is actually a light grey color. Rhodium is very white and very hard, but it does eventually wear. To keep a white gold ring looking its best it should be re-rhodium plated approximately every 12 months.

As each gold color contains the same proportion of pure gold, all gold colors with the same karat weight when measured on the Vickers scale have the same Vickers score.

There can be a difference in color between the different karats of gold.

18kt yellow gold is more yellow than 10kt yellow gold with 18kt yellow gold having a richer golden color making 18kt yellow gold a more popular choice of yellow gold than 10kt for ladies engagement rings.

10kt white gold and 18kt white gold have a similar white color due to the rhodium plating finish.

The following are your three main considerations when trying to decide between the gold karat types.

  1. The metals performance with every day wear
  2. The difference in color between the 10kt, 14kt and 18kt gold
  3. The difference in price between the gold karats.

18kt generally holds up to everyday wear better than 10kt and tends to look better than 10kt as it ages over the years. This is a primary reason why 18kt is normally preferred for ladies engagement rings rather than 10kt.