Frequently
Asked Questions
What type of Gold or Silver do you recommend for your arm bangles or rings?
When we make our astrological ayurvedic gem bangles in silver, they are composed of STERLING SILVER which is 92.5% SILVER and 7.5% COPPER.
Pure noble metals have a subtle benign frequency; the purer the metal, the more benefit there is to the wearer. Fine silver is too soft to use in the gem-mounted part of the bangle, it would not be durable. But the expandable spring links which make up the other portion of the arm bangle are available in both sterling silver and an extra thick walled pure silver version. We generally use the sterling silver spring links at $25 each, but upon request we will supply the customer with the pure silver spring links at the price of $38 each (as of January 2013).
When we make a gem bangle in gold, we always use 22 karat gold. Pure 24 karat gold is too soft for durable construction. We can make custom bangles in gold using less purity such as 14 karat gold, etc. but the expense is not justified, in our opinion, as the extra alloy neuters the ayurvedic properties of the gold. As is the case with silver, extra thick walled spring links can be made in 24K gold.
Astrogems always recommends alloys that use noble metals only. Silver, copper, and gold are noble metals and have harmonizing influences on the electrical body, whereas we have found nickel and zinc not to be as benign. We are quite different to most jewelers who do not have control over the casting process and tend to use metals with zinc, nickel and/or cadmium in the alloys.
CARAT or KARAT: The word has 2 meanings.
Referring to diamonds and gems, a carat is a unit of weight equal to 1/5 of a gram.
Referring to gold purity, one karat is 1/24 part. So 24kt is pure gold, 18kt is 18/24 or 75% gold, etc. Karat golds are alloys of gold with other metals. There are different standards throughout the world. 18kt is commonly used in Europe. Other commonly found ones are: 10, 14, 22kt. Gold is very soft unless alloyed. The alloys are also used often to vary the properties and color of gold (rose gold, for example).
PROPERTIES & CHARACTERISTICS:
Gold (Au) has a specific gravity of 19.32 (silver 10.5, platinum 21.45), Atomic weight 197.2.
Most pure metals are gray or silvery in color except for gold and copper. When gold contains large amounts of copper, compared to other alloying metals (like silver & zinc), a red or rose gold is produced. Many different rose golds have been alloyed and it is difficult to match an old rose gold with modern alloys. 18 kt red gold is a subtle warm rosy color. Yellow gold usually contains gold, silver, zinc and other metals to enhance hardness. Alloyed with silver (Electrum), it is very soft and is greenish-gold in color. 22kt gold is a very rich yellow color and is soft. White gold is usually from gold, silver and nickel (see table) and sometimes palladium.
DISCOLORATION:
Pure gold is a rich yellow color and does not tarnish. There is some tendency (not often, though) for karat golds to discolor. Sulfides in the atmosphere, sweat from skin, perfumes, and household chemicals can all contribute to this, although only the surface is affected and the tarnish can be polished away. White Gold is often more susceptible and can be yellowed by bleach. Antibiotics can alter the properties of sweat and promote discoloration of metals.
The compositions of alloyed gold or silver for the commonly used alloys are:
ALLOY NAME |
COMPOSITION |
BLUE 18K |
75% GOLD 25% IRON |
YELLOW 14K |
58% GOLD 4-28% SILVER 14-28% COPPER |
YELLOW 18K |
75% GOLD 10-20% SILVER 5-15% COPPER |
YELLOW 22K |
92% GOLD 4.2% SILVER 4.2% COPPER |
GREEN 18K |
75% GOLD 11-15% SILVER 13-0% CADMIUM |
RED 18K |
75% GOLD 25% COPPER |
STERLING SILVER |
92.5% SILVER 7.5% COPPER |
WHITE 14Kt CLEAN CAST |
58.3% GOLD 21.7% COPPER 11% NICKEL 9% ZINC |
WHITE 14Kt A |
58.3% GOLD 17% Nickel 17% COPPER 7.6% ZINC |
WHITE 14Kt B |
59% GOLD 25.5% COPPER 12.3% NICKEL 3.2% ZINC |
WHITE 18K |
75% GOLD 18.5% SILVER 1% COPPER 5.5% ZINC |
Please note that silver from countries such as Nepal and India commonly has Cadmium in it and that this metal has legal restraints in the EU due to its toxicity.
ALLERGIC REACTIONS:
These are most commonly caused by allergies to nickel; if so, white gold 'B' which contains the most nickel, should be avoided. We use clean cast 22kt gold as standard, which contains no nickel nor zinc so common to 14kt white gold alloys. We can make some of our jewelry in NON-NICKEL containing alloys of white gold. Just give us a call or email if you are in need of this type of gold.
ANNEALING:
Metals have a crystalline structure. When a metal is strained and distorted mechanically, the crystals become stressed and the metal hardens. To relieve this stress, and "relax" the structure, they must be heated to a temperature somewhat below the melting point. This is called annealing. Gold alloys must be cooled slowly after annealing. Our bangles are made in such a way that they can last a lifetime and will not need annealing.
MALLEABILITY:
Describes how the metal deforms under impact from a hammer or punch. After annealing, gold is generally quite ductile (soft). Fine 24 kt gold is softer than lesser karat gold alloys. Deforming metals by pressure or impact causes them to harden at differing rates dependent on the alloy. As it hardens, it becomes less deformable, and more brittle. Most alloys containing copper will age-harden. This may be apparent over months to years.
WEAR:
The wear resistance is related to its surface hardness and age as well as to the actual metal. For example, the annealed hardness of 10 & 18 kt golds are similar. 18, 14, 10 kt golds are considerably harder than 22 or 24 kt gold. Annealing softens them, and working (bending, twisting) tends to work harden metals (this explains why forged steel is much stronger than cast steel for the same alloy content).
SOME OTHER TRIVIA:
130,000 tons of gold have been mined so far (only 15% of this is missing). 42% of known gold lies in Central Banks.
Return
to Frequently Asked Questions
|