Oldest Jewelry

Curious about which is the oldest piece of jewelry we know of? Click here to read about it.

WHY WOULD ANYONE ALLOY GOLD

This is a write-up about why gold is alloyed? Why is it that this precious material is contaminated. Click here to read about it.

Friday, January 06, 2006

WHY WOULD ANYONE ALLOY GOLD

WHY ALLOY GOLD

Gold in its pure form is yellow in color and is called PURE GOLD or FINE GOLD. Its purity represented in KARAT. It is alloyed or mixed with other metals in a consistent blend for the following most important reasons:

To achieve the strength or stability in gold

• Pure gold is very soft and jewelry made in this kind can easily bend and get misshaped. Fine work such as filigree is usually not recommended in pure gold because it can bend out of shape to irreparable extents fairly easily


• Stones set in pure gold can easily fall out because of the softness of the metal holding them. Most commonly plain gold jewelry is made in 22 K in India and 14K or 18 K in the US.


• To make a product in higher karat gold, the thickness of the product has to be considerably increased to increase its stability. Thus you will land up paying more for the same design made in higher karat gold.

To achieve color in gold

Gold in its purest form is yellow. Gold is often alloyed with other metals such as silver, copper, zinc, palladium etc to achieve a whiter or paler look. “White” gold is an extremely pale color of gold which looks almost white. This is usually created in 18 K gold or lesser purity of gold.

• Normally the bright yellow of pure gold reflects off beautifully on darker skin tones. This makes 22 K yellow gold a popular choice in India as well as Africa. However, pale yellow colored jewelry looks beautiful on most paler or lighter colored skins and hence becomes a popular metal in the US, Italy and Australia. White gold is now a popular choice all over the world due to its publicity and resemblance to platinum.


• Other colors in gold are pink gold, purple, black, green and white. These colors depending on the properties of each are used to enhance design without compensating on the value of the product.

Workability increases when the gold is alloyed

• It is simpler to create solder (material used to join two pieces of gold) for a lower karat of gold rather than struggle with achieving the purity of 24 K gold.


• For a craftsman it is easier to work on lower Karat of gold most of the time if the product has to be hand crafted. He has to be much more attentive so as not to ruin his work when working with fine gold.


• For these above reasons, the making or labor charges may be lesser for a lower karat product in gold.

The cost of metal in a product is reduced considerably

• If in a 18K gold product, the value of metal used is $ 750, then the same design made in 24K gold will be $ 1000. The same design in 9K gold will be $ 375 only. Thus in a fixed budget one can get more if they are willing to compensate on the karat value of the metal.


• Since the weight of gold is more than that of silver or copper, (which is the most common alloying metal for making jewelry) hence the mass of 10gm pure gold will be lesser than that of 9 K gold.

• This means that a 10 gm gold bangle in 24 K is smaller to look at than the same design same weight in 9 K gold.

• Due to its softness, the higher the karat of gold, the faster it gets scratches thus requires more frequent polishing and hence the loss of precious material. This wear and tear makes the product look older sooner.

ABOUT THE ALLOYS

Pure or fine gold is 24 K and theoretically this means that the metal has 100% gold content in it.
But for making jewelry, an example of 18 K gold in terms of “fineness” is the gold content expressed in 750 parts per thousand (75.0% gold). The remaining 25% of the metals in this alloy can vary depending upon the property desired.

The percentage of gold in various alloys is given below (the commonly used Karat values are marked in bold).

1. 24 K = 24/24 * 100 = 100 % Gold; no other metal
2. 23 K = 23/24 * 100 = 95.83 % Gold; 4.17 % other metals
3. 22 K = 22/24 * 100 = 91.66 % Gold; 8.34 % other metals
4. 21 K = 21/24 * 100 = 87.5 % Gold; 12.5 % other metals
5. 20 K = 20/24 * 100 = 83.33 % Gold; 16.67 % other metals
6. 19 K = 19/24 * 100 = 79.16 % Gold; 20.84 % other metals
7. 18 K = 18/24 * 100 = 75 % Gold; 25 % other metals
8. 17 K = 17/24 * 100 = 70.83 % Gold; 29.17 % other metals
9. 16 K = 16/24 * 100 = 66.66 % Gold; 33.34 % other metals
10. 15 K = 15/24 * 100 = 62.5 % Gold; 37.5 % other metals
11. 14 K = 14/24 * 100 = 58.33 % Gold; 41.67 % other metals
12. 13 K = 13/24 * 100 = 54.16 % Gold; 45.84 % other metals
13. 12 K = 12/24 * 100 = 50 % Gold; 50 % other metals
14. 11 K = 11/24 * 100 = 45.83 % Gold; 54.17 % other metals
15. 10 K = 10/24 * 100 = 41.66 % Gold; 58.34 % other metals
16. 9 K = 9/24 * 100 = 37.5 % Gold; 62.5 % other metals
17. 8 K = 8/24 * 100 = 33.33 % Gold; 66.67 % other metals

Most jewelry worldwide is marked with the caratage or fineness. This may be part of a Hallmark on the jewelry. To read more about Hallmarking and Assaying of gold, please click here.

Something very interesting about gold alloys is that with varying quantity or percentage of alloying metals used, the physical and chemical properties of that alloy can be very cleverly manipulated. A very common use of this fact is that 18 K white gold and 18 K yellow gold has the same content of gold in them, but the color changes. 18 K pink gold is harder to work with than 18 K yellow gold. To read about these differences and how one can use these in their jewelry, click here.

Engagement rings for men

The recent query I got:

Is it true that engagement rings for men should not have diamonds? or is this
just a myth? – Miti Garg

To read about this, please click here

Flush Setting

FLUSH SETTING

In this kind of setting, the stone is set completely in the metal so that it looks like its surface is on the same level as the rest of the metal. It is the most stable kind of setting for the safety of the stone.Unfortunately, the stone in this setting has to endure a lot of tension while being set, and if not crafted with experience or care, it can easily get chipped or damaged. Thus the setting cost is a little on the higher side.

Also, in this kind of setting, the stone looks a little smaller and also the metal covers it enough to retard the light reflected back from it.

The other disadvantage of this kind of setting especially in case of deep cut stones is that the amount of metal used is much more than other conventional settings such as prong or bezel settings. The thickness of the metal has to be more than the depth of the stone, so most big stones are NOT set in this style unless manipulated by design technically.

This kind of setting is usually recommended for tougher stones such as Diamonds, Rubies, Sapphires etc. Almost all stones set in this setting look gorgeous especially when complimented with matte finish. This of course depends on the design itself.

"Today, jewelry designers view flush setting – sometimes called burnish setting – as an innovative alternative. Freed from the constraints of channel walls, prongs and groupings, flush setting allows a random, almost whimsical, scattering of gem accents." -by Tom Weishaar

Click here to learn how to set a stone in Flush Setting?