18 k gold and 900 Silver - What it really means

Current gold price - Tips for Buying Jewelry  (or everything you always wanted to know about precious metals but were afraid to ask)

An educated client is our best Customer!  

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 (we do not use nickel as it can produce an allergic reaction) 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. Please be advised that industry standards are white gold items are rhodium plated, it is used to enhance the luster and durability and gives a smooth, shiny finish to the jewelry.  White gold in its original form is yellowish.  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.

Specifically for 18k gold, If a jewelry item is 18 karats, this simply means that out of a total of 24 parts, 18 parts of the piece are gold, and 6 parts are made up of other metals.   Expressed in percentage terms, 18k is equal to 75% gold content (18 divided by 24.  The other 25% usually consists of metals such as zinc, copper, nickel, etc.  The additional metal in 18k gold serve to make the alloy harder and more durable than pure gold (24k) which is too soft for jewelry.  Be advised there is no set legal definition for what those other metals are, or an industry standard of percentage.  One jeweler may use more zinc, or copper as part of the 25%.  This will effect the color.  More copper will result in a darker gold, think of it as a paint palette, adding more of a certain color will give a different shade.

The same rules for keeping silver jewelry in good shape apply for gold. 

 

The Price of Gold

With the price of gold skyrocketing, we feel it is important to publish the minimum grams of gold your jewelry will weigh.  We feel you have the right to know exactly what you are getting.  This is a challenge with cartouche jewelry, as each on is hand crafted and depending on the symbols the weight will vary. In 99.99% of all cases your jewelry will weigh more than what we publish, we believe in erring on the side of caution.  We also feel it is very misleading to give ranges, i.e. 3 to 5 grams of gold, that is a significant range in jewelry.  Is that like being a little bit pregnant?  We are committed to giving you all the information you need to make a well informed purchase. 

Tips on weighing your jewelry.  Our scales are calibrated by the government on a regular basis to be accurate.  The jewelry industry standard for weight gold takes into account variables in different scales.  The acceptable range of difference is +/- 5 percent.

 

How do I test if my jewelry is 18k gold or 925 Sterling Silver?  There are several tests available.  We would recommend taking your piece to a reputable jeweler who uses electronic or x ray testing, XRF (X-ray fluorescence) is a non-destructive analytical technique used to determine the elemental composition of materials. XRF analyzers determine the chemistry of a sample by measuring the fluorescent (or secondary) X-ray emitted from a sample when it is excited by a primary X-ray source. Each of the elements present in a sample produces a set of characteristic fluorescent X-rays ("a fingerprint") that is unique for that specific element, which is why XRF spectroscopy is an excellent technology for qualitative and quantitative analysis of material composition.  Industry standard allows for up to a 2 -  5 %variance in karat.  This is a preferable method as other tests require scratching the surface to take a sample, which can mar the piece.  Acid tests should be done only by a professional, again it can mar the piece. 

What is not acceptable is opinions from a pawn shop.  It should come from a reputable jeweler who is accredited:  Meaning a certificate from a reputable institution has been issued and certifies this person can identify diamonds, gemstones and jewelry, and determine their value. They should be willing to provide his/her certification, the testing method and results on their letter head complete with signature, company name, address, phone.  This is applicable to silver as well.

Gold Price charts provided by goldprice.org

900 Silver compared to 925 Silver (Also known as Sterling Silver)

Statistics say 2-3% of people have skin chemistry that causes sterling silver alloys to turn their skin green, black, or grey.  If you have experienced this issue, please read the information below for causes, prevention, and solutions. 
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. 

Over time oxidation reactions will occur, 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.  BOTH types of silver will tarnish or develop a patina over time.

Silver tarnishes faster in areas with high humidity and air pollution. Additionally contact with materials like cosmetics, hairspray, perfume, deodorant, body lotion, bleach, etc., can speed up the tarnishing process. The silver in your ring may also become oxidized by reacting with acids in your skin, the moisture in perspiration, or by reacting with some other lotion or chemical on your skin. Below are some common culprits

1. Cosmetics

Make-up present on the skin or clothing is the most common cause of blackening or smudging. Cosmetics often contain chemical compounds which are harder than the jewelry itself. These compounds can rub off very tiny particles of metal which appear as jet black dust.

Solution: Use a silver cloth to polish your jewelry. Remember to remove rings & jewelry while applying make-up. Using soap & water, clean the areas of your skin that will come into contact with the jewelry making sure all soap is rinsed off and your hands are dry

2. Moisture & Humidity

Moisture in the air or on the skin can react with the copper present in all Sterling Silver jewelry, causing a green discoloration and tarnish to develop. This is a fairly common complaint in hot, humid climates and can also affect individuals with particularly moist skin.

Solution: Using a silver cloth, polish your jewelry frequently. You might also use an absorbent powder on those moist skin areas which come into contact with your jewelry. Keep your silver jewelry out of the bathroom and shower area. Leave your silver jewelry at home when you go to the gym or spa.

3. Contact with Sulpher Compounds

Sulpher compounds can also cause Sterling Silver to tarnish. Avoid wearing your jewelry in heavily polluted environments. Also be careful when handling coal or oil, and when preparing foods containing sulphur such as eggs, onions, fish or shellfish

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.  Salt air, perfume, hairspray can also affect the finish.

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.