Some general tips to keep your treasures in great condition long after they are with the Jeweler and general jewelry FAQ's.


Clean diamonds and most color gemstones in warm, soapy water with a soft toothbrush. We find the brand Simple Green to be perfect for most stones and metals. Rinse completely and dry with a clean, soft cloth.

Consult Gallery Jewelers for the special care of your emerald, opal and pearl jewelry.

Remove your jewelry before showering, swimming, cleaning, sleeping, doing rough work or handling harmful chemicals - including hair care products and perfume.

Bleach and pool chlorine, specially when warm (as in hot tubs) is the most damaging to the metals in your jewelry, repeated or long contact with hot chlorine can completely dissolve white gold! Platinum and high carat yellow gold are less likely to sustain damage.

Do not expose gemstone jewelry to sudden temperature changes, which may cause cracks.

Store each piece of jewelry separately to prevent them from scratching each other.

After wearing your pearls, wipe them with a clean, dry, soft cloth. Strange as it may sound, water can damage your pearls! Tap water may contain harmful minerals that will deposit on your pearls silky luster, rendering them dull and "scratchy". If you must rinse your pearls (like after a spill) use distilled water if possible, or bring them into the shop for a professional cleaning and inspection.

 

What is White gold?

White gold is an alloy of gold and some white metals such as silver and palladium. White gold can be 18ct, 14ct, 10ct or any karat. For example, 18ct yellow gold is made by mixing 75% gold (750 parts per thousand) with 25% (250 parts per thousand) other metals such as copper and zinc. 18ct white gold is made by mixing 75% gold with 25% other metals such as silver and palladium. So the amount of gold is the same but the alloy is different.

Traditionally nickel was used in white gold, however, nickel is no longer used in most white gold made today as nickel can cause reactions with some people. We generally do not use or sell nickel in our white gold.

When white gold rings are new they are coated with another white metal called Rhodium. Rhodium is a metal very similar to platinum and Rhodium shares many of the properties of platinum including its white color.

The rhodium plating is used to make the white gold look more white. The natural color of white gold is actually a light grey color. The Rhodium is very white and very hard, but it does wear away eventually. To keep a white gold ring looking its best it should be re-rhodium plated approximately each 12 to 18 months. Gallery Jewelers is able to rhodium plate jewelry for a cost effective price.

 

Why am I allergic to some gold jewelry?

Every year we get a few customers who believe that they cannot wear gold jewelry because they get an allergic reaction to it. Some believe that they are allergic to gold. We have never yet known anybody who was allergic to pure gold, and seems very unlikely as gold is inert and not active in the sense of corrosion or decomposition over time, nor is it acidic.
The most common cause of allergic reactions to jewelry is nickel contained in the alloy. Nickel is, or was, frequently used in white gold alloys because it is inexpensive, hard, and has a strong whitening effect. Better quality white gold alloys use palladium, which has excellent properties but is more expensive.

Commonest Causes
The next commonest cause of allergies for jewelry wearers appears to be detergent or other chemicals which lodge between the jewelry, usually rings, and the skin. Hairdressers are often affected. Rinsing well can help, but it is probably best to remove rings before using any troublesome chemicals, and use a barrier cream.

Other Causes
A few jewelry wearers still seem to be slightly allergic to yellow gold's, nickel cannot be the cause because it is not used in yellow gold alloys. In most cases sufferers only experience problems with low gold content alloys such as ten carat, so upgrading to a better alloy such as eighteen carat usually solves all problems.

Higher Carat Gold
The other common components of ten carat gold alloys are copper, silver and zinc. Zinc is usually very well tolerated, it is used in many medical preparations. Silver and copper do not usually cause allergic reactions, but both will form compounds with atmospheric pollutants which may be the cause of some reported problems. When copper and silver are present in high carat alloy such as eighteen or twenty two carat, they are more resistant to attack by chemicals, because they are bound more closely with the gold content, and this will explain why high carat alloys cause fewer problems.

Anti-Perspirants
Strange as it may seem, but using anti-Perspirants can exacerbate metal allergy problems. It has been found that the sweat of a healthy person in a sauna can contain 20 times the nickel content of blood plasma, this may help to explain why exercise can improve health. Anti-Perspirants can reduce the bodies natural way of eliminating heavy metals. Healthy natural lifestyles tend to improve health, whereas unnatural practices can cause problems.

Allergies to Buying Jewelry
Of course some men think they are allergic to jewelry, mostly they are just allergic to buying it for their wife because they would rather put the money towards a new BMW, Jag, Ferrari, or such other toy.

Carats or Karats and laws

Two Different Meanings
The word carat (or also correctly "karat") has two distinctly different meanings, both used in the jewelry industry.

  • Carat Weight
    When the word "carat" is applied to gemstones, including diamonds, it means a unit of weight. A carat is equal to one fifth (0.20) of a metric gram. It is actually incorrect to refer to a "1 carat sized" diamond, it should be referred to as being a "1 carat weight" diamond.

 

  • Carat Gold Alloys
    A carat is 1/24th by weight
    A carat as applied to gold alloys means a proportion by weight of one part in twenty-four, 4.166%, or 41.66 parts per 1000. The higher the carat value, the higher the proportion of gold in relation to the base metal content. Pure gold is therefore 24 carat.

 

  • 9 Carat Gold Laws
  • In 1976 the United Stated Gold and Stamping act was modified by the Plumb Gold laws and 9K Gold was no longer allowed to be sold (new) as Gold and stamped with a K marking.

 

Is it correct that 10 carat gold is harder wearing than 24 carat gold?
The simple answer is no!

Surprised?
Most people are surprised to hear this, because for some reason, they have always believed, or been told, that 10 carat gold is harder, or harder wearing than 24 carat gold. We sometimes have trouble convincing them, sometime they will not believe us until they see it in writing. That is why we have put it in writing, and included it in our leaflets and sales literature for some years now.
Why then does everybody tell you that 10 carat is harder?
What we have wondered for many years, is how and why people get to believe that 10 carat is harder. I believe there are two reasons why this myth has become established:-
 

  • Ignorant Sales Staff
    Firstly, sales staff in jewelry stores do not always know their facts, and because 10 carat gold is more commonly stocked than 18 carat, they try to sell what they have in stock, therefore it is tempting to sell the benefits of 10 carat gold. I believe that staff in many multiple jewelers have long done this, probably out of ignorance; hopefully things are changing.

 

  • The Obvious Assumption is Wrong
    Secondly, it is fairly well known that pure gold is quite soft, too soft, in fact to be used successfully in jewelry. This is quite accurate, although in some cultures, consumers prefer pure gold jewelry, but it is rather soft, so it needs to be made quite solid for greater strength, and this adds to the price. Pure gold jewelry also would need to be worn with more care than alloyed gold jewelry. It is also fairly well known that if gold is alloyed with other metals, it becomes harder. Where many people make a mistake is to assume that the more "other" metals are added, the stronger and harder the resultant alloy. This is an easy and understandable mistake to make, and I believe that both consumers and many working within the jewelry trade have commonly made the same mistake over a long period of time, until the mistake has become lazily accepted as the truth.
     

Is there a more complete answer?
As usual, the answer to a simple question is not always simple.
First, there are many different combinations of metals which can be used to make gold alloys. There are many different "recipes" for both 10 carat and 18 carat gold alloys. A carat simple means 1/24th, i.e. one part in 24. So
10 carat gold must be at least 10 parts gold out of 24, which is equivalent to 41%, the other 59% can be any other metal, the commonest used being copper and silver, but nickel, palladium, zinc, and other metals are used. Similarly with 18 carat gold, which has to be 18/24, equivalent to 75% gold, the rest being composed of any other metal. You would be quite correct to guess that each different "recipe" has its own different characteristics including hardness. It is quite possible to make hard or soft "recipes" for 10 carat and also for 18 carat and other gold alloys. In general, most common 18 carat gold alloys are both harder, and harder wearing than their 10 carat equivalent.

Durability
This brings is to the point that hardness and durability are not one and the same thing. To give a simple example, a glass ball is harder than a rubber ball. Try throwing each onto a hard surface. The glass ball will break, but the rubber ball will bounce at remain intact, because the rubber ball is more durable than the glass one. The glass ball breaks because it is brittle. In the same way, metal alloy can also be brittle, and 10 hard carat gold alloys tend to be slightly brittle, whereas 18 carat gold alloys tend to be more resilient.

Tarnish Resistance
18 carat alloys are almost completely resistant to chemical attack in normal use, whereas 10 carat alloys are much less resistant. Ten carat alloys for example will go dull or even black merely from exposure to chemicals in the atmosphere, they will also discolor in contact with perspiration, some fabrics, bleach and other household chemicals.

Metallurgy & Alloys
To understand more fully, a little metallurgy is necessary. Each and every pure metal will have a particular hardness which will not vary much. If it is worked by rolling, stretching, bending, hammering, or other mechanical process, it will tend to become harder but more brittle. It can usually be annealed or softened by heating it. Two or more metals mixed together form an alloy. Alloys differ form pure metals, in that they often combine some of the mechanical properties possessed by their constituent metals, but often also in other less predictable ways. Many alloys for example can be hardened or softened by appropriate heat treatment. Heat treatment include heating to a variety of high or low temperatures for long or short periods of time, followed by cooling at different rates. Each alloy will have different hardness figures depending on its state. Common states to be considered include: just cast, after casting and annealing, after age hardening (heat treatment), after cold working, after cold working followed by stress relieving, and others.

Hardness Table for Carat Gold Alloys
Although, as we have explained, there are many different alloy "recipes", to give you an indication of the hardness figures for 10 and 18 carat gold, the following table gives a range of typical "Vickers" hardness values for fairly common "recipes":

 

Alloy Hardness as Cast Maximum Annealed Hardness
10 75 to 125 160 to 170
14 125 to 165 150 to 180
18 85 to 125 170 to 230
22 70 60 to 90
23.75 40 70
Silver 65  
Platinum SC 65  
Platinum HC 135  

Key to Table
Silver = Typical sterling silver (925/1000)
SC = Soft casting alloy
HC = Hard casting alloy

What About 14 Carat?
Some observant folk may notice that 14 carat golds are quite hard as cast, and this is fairly accurate. In fact this can make 14 carat slightly difficult to work with in some manufacturing processes, especially for jewelers working mainly with 10 carat or 18 carat alloys. However, you will also notice that the 18 carat alloys tend to be harden-able to a higher figure than 14 carat, and providing that both standards had been correctly worked and conditioned, then the 18 carat alloys would almost always be both harder and harder wearing.

The Best
To finish with a very simple personal opinion. If there had to be only one single gold alloy purity standard, then I believe that 18 has such excellent all round properties that it would deserve to be the winner.

Density of Gold, Silver, Copper, Platinum & Other Jewelry Metals
Every week several people ask us questions about the weight or density of gold. A typical question is "What does a cubic meter / foot / inch / centimeter of gold weigh?". Because we do not have the time to give each enquiry an individual reply, we have provided this page for your information.

Density and Specific Gravity
For most practical purposes, density and specific gravity are the same, however there are slight differences between them, as most scientists would appreciate.

Density
Density is defined as the ratio of the mass of an object to its volume.
Density should correctly be expressed in units of "unit mass per unit volume", e.g. grams per cubic centimeter. The figure quoted is often the same as that for specific gravity. For those who are unsure what "mass" means, consider it to be the same as "weight", you will not be far out.
For the benefit of Nottingham University students, please note that the figure for S.G. is the same as the figures in grams per cubic centimeter = tons per cubic meter = S.I. units.

Specific Gravity
Specific gravity is defined in Webster's dictionary as the ratio of the weight or mass of a given volume of a substance to that of another substance (usually water for solids and liquids) used as a standard.
Specific gravity is not expressed in units as it is purely a ratio.

Specific Gravity Table
All figures quoted are approximate. Please note that actual densities may vary according to the exact physical state of the metal, as cast, rolled, drawn, because of varying degrees of porosity, and its temperature.
Alloys will vary considerably according to the other components they contain.

Metal Density
Gold 19.3
Silver 10.5
Platinum 21.4
Palladium 12.0
Copper 9.0
10ct 10.9 to 12.7
14ct 12.9 to 14.6
18ct Yellow 15.2 to 15.9
18ct White 14.7 to 16.9
22ct 17.7 to 17.8
Sterling Silver 10.2 to 10.3
950 Platinum 20.1

Other Facts about Gold Weight
It follows from the above table that:-

  • A cubic centimeter of gold will weighs 19.3 grams.
  • A cubic meter of gold will weighs 19.3 tons.
  • A cubic inch of gold will weighs 315.2 grams = 10.13 troy ounces = 11.06 avoirdupois (ordinary) ounces.
  • A cubic foot of gold will weighs 545.225 kilos = 1188.6 pounds (avoirdupois).

We hope this helps!

Credit for most of this page goes to http://www.24carat.co.uk/

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