If a piece of platinum jewelry is marked "Platinum" then it contains at least 95 percent pure platinum. Jewelry with 85 to 95 percent pure platinum is marked "950 Plat." or "950 Pt.," "850 Plat." or "850 Pt.," etc. Both the two- and four-letter abbreviation for platinum is used.
850 – 85% Platinum. 900 – 90% Platinum. 950 – 95% platinum. 999 – Pure (very little metals added) Platinum. Once you have determined what type of metal your jewelry piece is made from, you can then more easily determine the value of your piece.
Sterling Silver pieces are stamped with either “sterling silver”, or the numbers 925. You may encounter other numbers, such as 850, an alloy that is often used to make flatware. The silver content of this alloy is 85%.
European silver (800): Sometimes referenced as continental silver, this is another non-sterling type of silver alloy. Marks can include 800, 825, 830, or 850, indicating 80, 82.5, 83, and 85% silver content, respectively.
850 means “850 fine” (if gold), or 85% silver.
Triton Tungsten Carbide TC. 850™ stands for a formula consisting of approximately 85% Tungsten Carbide, yielding a strong, heavyweight, hypoallergenic and tarnish resistant material. This uniquely forged metal is perfect for a day to day activity.
Look for a Letter Mark
If the item of jewelry has the letters GP, GF, or GEP stamped on it, these indicate that it is not made of real gold. GP means it is gold plated, GF means it is gold filled, and GEP means it is gold electroplate. That is, the jewelry is made of some other metal with a thin layer of gold on top.
999, for example, is the purist amount, essentially 24 karat gold with a 99.9999% purity. On the other hand, 750 is indicative of a 75% purity level, better known to most as 18 karat gold. The 3-digit stamp sequence generally gets identified as follows: 999.9 or 999 – 24 karat gold.
Pure silver or fine silver, is the most valuable form of silver that contains 99.9% silver and 0.1% other metals. This type of silver is known for its high luster and lack of tarnish. Fine silver jewelry will usually have a “999” or “FS” mark somewhere on the piece.
Authentication Hallmarks
International sellers of silver will stamp silver as 925, 900 or 800." These numbers indicate the level of purity of the silver. Sterling silver has a purity of 92.5 percent or higher.
Fine silver has a millesimal fineness of 999. Also called pure silver, or three nines fine, fine silver contains 99.9% silver, with the balance being trace amounts of impurities. This grade of silver is used to make bullion bars for international commodities trading and investment in silver.
A: The 825 stamp on jewelry is the same as 19 Karats of gold; for example, an 825 ring represents a purity rating of 82.5 percent, meaning an 825 ring contains more than 82 percent gold. The 825 stamp on jewelry means that 825 parts out of 1000 are gold (82.5%).
Gold-plated pieces may be marked 'GP,' 'GE,' or 'HGE. ' 'GP' or 'GE' means the piece is electroplated with a thin layer of gold; '18K GP' would indicate a piece plated with 18 karat gold.
Gold Purity Marks
The letter “k” refers to karats, where pure gold is composed of 24 karats (24k). A piece of jewelry with an etching that reads “18k” or “750” indicates that it is made up of 75 percent gold, while a “14k” or “585” mark indicates the metal is constructed with 58.5 percent gold.
In Australia there has never been and still isn't a silver or gold marking required on items. It is of course in the best interest of the jeweller to mark their jewellery and many did. Silver pieces are often only marked STG SIL, STG SILVER or Sterling Silver.
Acid test.
An acid test can reveal the karat of solid gold jewelry, but it can also show whether jewelry is solid gold or gold-plated. With an acid test, a small sample of the jewelry is removed and exposed to acid to induce a color change. The resulting colors indicate which type of metal the jewelry is made of.
Look for Stamps or Hallmarks in Your Gold Jewelry
Most real gold is stamped with a hallmark that indicates its purity, aka its karat. The karat is the unit used to measure the purity of gold. The higher the karat, the purer the gold. The most common karats you'll see are 10k, 14k, 18k, 22K, and 24k.
What to do: Hold the magnet up to the gold. If it's real gold it will not stick to the magnet. (Fun fact: Real gold is not magnetic.) Fake gold, on the other hand, will stick to the magnet.
18K gold contains 75% gold, and the imprint reads "Au750." When gold is mixed with other metals, the alloys show colors ranging from pale yellow to rose, or even white. Yellow gold is a mixture of copper, silver and gold. White gold has higher silver content, whereas higher copper percentage gives rose gold.
Other markings may include numbers like 583 or 585. These are popular European gold markings. There are also markings that indicate a chain is not a real gold chain. GP, RGP, GEP, HGP, and HGE are all markings that signify a chain is gold-plated or gold-filled and not solid gold.
The metal purity or fineness mark refers to how much of the precious metal is actually in the ring. It consists of a three digit number within a shape. 375 is 9ct and means that 9ct gold is made up of 37.5% pure gold and is mixed with other metals to create the piece.
Platinum jewelry should be stamped “PT” for pure platinum or “PT900” or “PT950,” indicating the number of parts per thousand that are pure platinum.
What is Gold 750? If a gold product bears the hallmark '750', then your gold has been tested and classed as 18 carat or 75 per cent pure. The remaining 25 per cent of the item is composed of different metals such as nickel, copper, or in some cases silver.