Definitions

Karat also spelled Carat, a measure of the fineness (i.e., purity) of gold. It is spelled carat outside the United States but should not be confused with the unit used to measure the weight of gems, also called carat. A gold karat is 1/24 part, or 4.1667 percent, of the whole, and the purity of a gold alloy is expressed as the number of these parts of gold it contains. Thus, an object that contains 16 parts gold and 8 parts alloying metal is 16-karat gold, and pure gold is 24-karat gold.

This system of indicating the relative proportion of gold originated with a medieval coin called a mark. A mark weighed 24 carats (in this case, the carat was the same as that used in the weighing of gems and was theoretically equal to the weight of the seed of the coral tree). Pure gold could not be used to produce marks because it was too soft, so copper or other metals were added to produce a hard alloy; the purity of the coin was then expressed by the proportion of its carat weight that was actually contributed by gold.

Because pure gold is too soft to resist prolonged handling, it is usually alloyed with other metals to increase its hardness for use in jewelry, gold ware, or coinage. Most gold used in jewelry is alloyed with silver, copper, and a little zinc to produce various shades of yellow gold or with nickel, copper, and zinc to produce white gold. The color of these gold alloys goes from yellow to white as the proportion of silver in them increases; more than 70 percent silver results in alloys that are white. Alloys of gold with silver or copper are used to make gold coins and gold ware, and alloys with platinum or palladium are also used in jewelry. The content of gold alloys is expressed in 24ths, called karats; a 12-karat gold alloy is 50 percent gold, and 24-karat gold is pure.

Gold Price charts provided by goldprice.org

900 Silver
The proportion of silver in these alloys is stated in terms of fineness, which means parts of silver per thousand of the alloy. Sterling silver contains 92.5 percent of silver and 7.5 percent of another metal, usually copper; i.e., it has a fineness of 925. Jewelry silver is an alloy containing 80 percent silver and 20 percent copper (800 fine). Therefore, 900 silver is 90 percent silver and 10 percent copper.  For jewelry in Egypt - there is no sterling silver. 

Over time oxidation reactions will occur, especially with sulfur and oxygen, causing silver to become tarnished. Tarnishing on silver jewelry, when worn on a regular basis, usually does not occur. Storage for a prolonged time causes silver jewelry to tarnish. Contact with rubber bands may cause tarnish - the sulfur in rubber is a catalyst for tarnish. Taking a medication that changes the acidity of your skin may cause silver jewelry to tarnish. Individuals with a more acidic PH balance will notice their silver jewelry tarnishes.

At all costs, KEEP OUT of chorine pools, lakes, rivers, salt-water ocean if you have your jewelry on.  This will take the luster and shine from your jewelry which will be hard if not impossible to ever get back.  This is applicable for gold as well.

Never wear jewelry when you are doing any kind of rough work. Even though it can be pretty tough and durable, it can still bend and scratch under certain circumstances.

To keep your silver tarnish-free, clean your silver in a mild dishwashing liquid diluted in water. Thoroughly dry your silver jewelry after exposure to water. Store silver in a dry container or a plastic bag with anti-tarnish paper.

Don't wear to bed or when getting wet.  Because silver oxidizes, it should not be worn 24 hours a day.  It is a good idea to take your jewelry off before bed and store it properly so it will maintain its luster.  Wearing silver while showering or swimming will likely tarnish it quickly.   Enameled pieces in gold or silver should not be exposed to water, or cleaning agents.

As with gold, don't expose silver to chlorine, sulfur or strong household cleaning supplies since the harsh chemicals can erode the quality and sheen of the silver.

We do not recommend cleaning your jewelry with toothpaste and a toothbrush as you will be scratching the silver or gold.

The best way to clean your jewelry is with a professional jewelry polishing cloth. The cloth is treated with cleaning chemicals and not only will the cloth last a long time, it will give you an amazing shine each and every time.

What is platinum?

What's the difference between platinum and gold?

Platinum is over 20 times rarer than gold.  It takes 10 tons of ore to get one ounce of platinum, gold takes 3 tons of ore for one ounce of gold.

Platinum  is more difficult and consequently more expensive to refine.

Platinum is almost double the weight of 18k gold.

Platinum will never wear out.

What's the difference between platinum and white gold?

White gold is a less expensive "white metal", white gold is man made and does not occur naturally in nature.

What's the difference between platinum and silver?

Platinum is the most precious of white metals.  Both platinum and silver have the appearance of a white metal, but platinum is extremely durable and resists tarnishing.. 

Be aware that over time platinum develops a natural patina that many people prefer over the "just polished" appearance of platinum.  When this happens to your platinum jewelry you may take it to a qualified jeweler and have the item polished for that "high gloss" look or simply ask them not to remove the patina if that is your preference.  Do not electronically clean platinum plated jewelry, polish it only!