Category Archives: Forum Questions

Is there any way to tell if my platinum ring is pure platinum? — Beth in Stillwater, OK

The two most common purities of platinum used in jewelry are:

Plat – 950 Plat is considered nearly pure platinum and usually contains 95% platinum and 5% iridium.  It is quite expensive and typically the highest grade of platinum available for jewelry making.

IridPlat – This platinum is 90% pure platinum with 10% other metals mixed in…typically iridium. These rings can be marked with a hallmark of “.90 Plat” as well and therefore have a slightly lower melt value than their purer platinum counterparts.

Obviously pure platinum will yield higher returns, however at around $1,322.00/troy ounce, platinum alloyed with other materials can return a surprisingly high melt value.

Is there an easy way to tell what grade a silver item is? — Austin in Naperville, IL

The easiest way without testing equipment or chemicals is to look for hallmarks that indicate whether an item is sterling silver.

You may notice small markings on items, usually found in the inside of rings, on clasps of necklaces or on the back of plates. These markings are called hallmarks and can indicate what type of metal you have and how much it may be worth. They are often extremely small so you may need a magnifying glass to read them.  As long as you bought the item from a reputable source, they tend to be very accurate.

Sterling silver items are called Sterling, Sterling Silver or Solid Silver and they are typically marked with 925, 925/1000, 92.5 or .925. The abbreviation SS is also commonly seen for sterling silver. These markings reveal that the item is made from 925 parts out of 1000 of fine silver, the minimum allowable quality for an item to be considered sterling. It is the law that the name or U.S. registered trademark of the company or person is on a quality marked silver item.  We will often ask people the brand and make of their silverware so that we can help them determine whether their silver flatware is sterling or plated although our testing equipment ultimately tells us for sure once we get the items into our facility.

For older pieces, silver may come in many more varieties.  800 silver which was 800 parts silver was very common outside of the United States and before the 1900s as were other 750, 825, and 830.

Another common form of silver on older items is 900.  It refers to coin silver which is 90% silver and 10% copper.  It’s composition was dictated by United States FTC guidelines and established in the 1820s for minting silver coinage.  As such, it is often called “coin silver.”

For further information, see video on refining silver flatware.

I am an avid metal detector user and am studying up on some of the industry terminology as I prepare to get some of the items I have found refined. For example, what is meant by “gold filled”, “troy ounce” and “pennyweight.” — Rick in Louisiana, MO

Thank you for you inquiry, following are some of the common terms used in the precious metal refining industry.

Carat – a unit of weight for gems
Karat (K, kt) – is measure of purity for gold
Fineness – the proportion of pure precious metal in an alloy, often expressed in parts per thousand
Fine Weight – the metallic weight of a coin, ingot or bar
Gross Weight – the total weight of an item, including the alloying metal
Gold Standard – a monetary system in which a region’s common medium of exchange are paper notes that are normally freely convertible into pre-set, fixed quantities of gold
Hallmark (plate mark) – an official mark or stamp indicating a standard of purity, used in marking gold and silver articles.
Luster – a substance, as a coating or polish, used to impart sheen or gloss
Ounce – a unit of weight. In the precious metals industry, an ounce means a troy ounce equal to 31.1035 grams
Spread – the difference between the buying price and the selling price of a precious metal
Troy Ounce – a unit of weight equal to 480 grains or 1/12 of a pound
Grain – the smallest unit of weight
Face Value – the nominal dollar amount assigned to a security by the issuer
Retail Value – the sale of goods or articles individually or in small quantities directly to the consumer
Pennyweight (dwt, pwt, PW) – a unit of mass which is the same as 24 grains, 1/240th of a troy pound, 1/20th of a troy ounce, approximately 0.055 ounces or approximately 1.555 grams
Hardness (HV) – sometimes called “scratch resistance,” the Vickers Hardness scale tests hardness of a metal by pushing a pointed object into the surface with a specific load and gauging penetration
Metal – any category of electropositive elements that usually have a shiny surface; typical metals are from salts with non-metals, basic oxides with oxygen and alloys with one another
Salt – crystalline chemical compound formed from the neutralization of an acid by a base containing a metal or group acting like a metal
EPNS – electroplated nickel silver or silver plate
Gold Filled (G.F.) – an item that has a thin outer layer of gold over a base metal. Items must be at least 1/20 gold by weight to be called gold filled
Gold Rolled (R.G.P) – Popular during the 19th century where a very thing sheet of solid gold is laminated to a lesser metal then fused together
Gold Plating – also referred to as electroplate (GEP), is a process where one metal is coated with another metal using electricity
Pinchbeck – gold substitute made with a combination of 9 karat gold, copper and zinc
Vermeil – usually gold plated sterling silver

Are there any precious metal terms we left out that you would like to know?

Are there differences in melt values between White Gold and Yellow Gold? — Sue in Cleavland, Ohio

For the most part, gold jewelry of the same karat value will have about the same melt value whether it is white gold or yellow gold. Aside from 24 karat (pure gold), all other karats of gold are alloys that include some other metals in them.  For example, an 18 karat gold item is about 75% gold alloyed with other metals that in turn affect the item’s color and hardness. Palladium and nickel are often used to create white gold while copper and silver are used for yellow gold.

Of course, nickel has dermatological health issues with it and palladium is expensive, so some white gold alloys actually include magnesium or chromium. Today, you are more likely to find rhodium plated gold as this metal often provides the look that consumers want, but the cost is so high that it is typically just plated onto the gold.  As a general rule, there is usually not a significant difference in melt value between an 18 karat yellow gold ring and an 18 karat white gold ring of the same weight.

24 karat gold is 99.84% gold (not achievable in white gold)
22 karat gold is 91.52% gold  (not achievable in typical white gold)
20 karat gold is 83.33% gold
18 karat gold is 74.88% gold
14 karat gold is 58.24% gold
10 karat gold is 41.60% gold
9 karat gold is 37.44% gold

I am a dentist and have some old gold crowns that I have recently taken out of patients mouths. At what point does it become profitable to send them in for refining.  Do I need to have 20-30 crowns before it makes sense? — Dr. Norton

It can be hard to judge how much precious metal is in dental gold scrap because so many different alloys are used in the industry. Typically dental gold alloys range in the 10 to 22 karat range with 16 karat gold being the most common.  A 10 karat crown would have 41.6% gold while a 22 karat crown would have 91.5% so there can be a big difference in value even for two crowns of the exact same weight.

Dentists also use a lot of silver-colored alloys for crowns and bridges that can have high precious metal content.   Despite their color, they may have a fairly sizeable proportion of gold or be made with other precious metals like platinum or palladium.  Unfortunately, without testing equipment, it is often difficult to tell the difference between these precious alloys and other “white” alloys that have no scrap value whatsoever.

Of course, the price of gold on the day your gold crowns are received for refining will also impact the value.

The last major variable is who you are going to sell  the scrap dental gold to.  If you sell it to the same company that is supplying you with other dental products, then they are probably just going to take a cut and pass the crowns to a precious metal refiner.    However, if you only have one or two, they may batch it with crowns and bridges from other dentists as many refiners will not accept small quantities.
If you work with us at Arch Enterprises, you do not need a minimum quantity of dental gold to receive payment. We will evaluate your items and pay you based on the weight and quality of the gold in the crowns. We have analytic equipment that can evaluate each piece individually for the gold, silver, platinum and palladium content. We pay 85% of the metal value back to you in a check in 2-3 business days.  We are endorsed by dental associations and have worked regularly with many dentists.

If you need some basic guidelines, let’s assume that the average crown weighs 2.5 grams or about .08 troy ounces (the value in which gold is traded) and that the price for the day is $1,000 per troy ounce.  Based on this, a

• A 2.5 gram crown made of 10 karat alloy (41.6% gold) would be worth (.08 x.416 x 1,000) or $33.28 before refining costs of approximately 15%
• A 2.5 gram crown made of 16 karat alloy (66.6% gold) would be worth (.08 x.666 x 1,000) or $53.28 before refining costs of approximately 15%
• A 2.5 gram crown made of 22 karat alloy (91.5% gold) would be worth (.08 x.915 x 1,000) or $73.28 before refining costs of approximately 15%