carreradmin, Author at Carreras Jewelers

METAL ALLOYS, What makes up Metals

August 6, 2013 8:50 pm Leave a Comment

Yellow Gold contains Gold, Silver, Copper, Zinc

Pink Gold contains the same metals as yellow gold, but has a higher percentage of copper that gives it the pink or rose hue.

Green Gold also contains the same metals as yellow gold, but a higher percentage of silver gives it a green look.

22k Gold has the 24k look but is made harder for jewelry and dental use by adding 8.3% alloy

24k Gold is a very soft and malleable metal in its pure form. It can be made slightly harder by drawing or rolling the metal.

White Gold contains gold, copper, nickel, and zinc. Most alloys use nickel as the whitening agent. The metals are whiter than palladium white golds but are not as malleable

Palladium White Gold (14k & 18k) are superior to white golds alloyed with nickel. The palladium gives the white gold a slightly grayer color than nickel white gold.

Pure Platinum is very malleable. For jewelry use, 10% iridium is added as a hardener.

Palladium is one of the platinum group metals. The others are iridium, platinum, ruthenium, osmium, and rhodium. Pure palladium is soft and malleable which makes it very good for pave work. 5% ruthenium is added to harden the palladium for jewelry use.

Fine Silver is very soft and malleable. No other metal has this white color, although .999 fine silver can tarnish over time. Sterling silver is used for jewelry because it is more durable than fine silver. 92.5% fine silver is alloyed with 7.5% copper to make sterling.

Why Jewelry sometimes Blackens the Skin or Clothing

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Blackening or discoloration of either the skin or clothing or the jewelry itself is certainly very annoying. There are several causes for these occurrences.

Metallic Abrasion:

Make-up present on the skin or clothing is the most common cause of the blackening or smudging. Cosmetics often contain chemical compounds, which are harder than the jewelry itself. Metallic abrasion occurs when these hard compounds come in contact with the jewelry metals and wear or rub off very tiny particles of metal which appear as jet black dust.

We recommend that you remove your rings and other metal jewelry while applying cosmetics.

Corrosion:

Discoloration can be caused from corrosion of the metals from which jewelry is made. Pure gold will not corrode but is too soft for jewelry so it is alloyed with base metals- usually silver or copper. Only the base metal used for alloying corrodes, leaving the gold untouched. The chemical compounds of silver and copper, which are formed, turn very dark even when slightly corroded. This corrosion occurs under moist or wet conditions.

Our skin, on which the jewelry lies, is provided with thousands of perspiration glands. These essentially mild chemicals are enough to cause corrosion of 14kt gold especially when aided by warmth and free access of air.

When this happens, we suggest that you remove your jewelry often and use an absorbent powder, free of zinc oxide, on the skin areas that may come in contact with the jewelry.

Rings containing copper and silver alloys, particularly sterling silver, corrode readily on the skin if enough salt is present. Rings should be removed when exposed to salt.

Tarnishing of Sterling Silver Jewelry:

Sterling silver is a copper-silver alloy and is somewhat softer than most gold alloys. It is more likely to be abraded to black dust by relative movement between the jewelry and the skin or clothing. Sterling silver has a pronounced tendency to tarnish. The tarnish is always due to the contact with sulfur compounds. The main cause of tarnishing of silver is a trace of hydrogen sulfide gas in the air.

The tarnish may turn the jewelry black and may also be rubbed off on the skin or clothing. A few people with especially moist skin may find that the sterling silver stains their skin green. This is due to the copper component of the silver alloy.

When this occurs, the jewelry should be polished frequently and use an absorbent powder on those moist skin areas.

Soap, detergent, wax, polish and cosmetic creams may build up under a ring, causing a type of dermatitis. A burning sensation and redness of the skin results. To prevent this, you should remove all rings before using soap or detergent and clean your jewelry frequently.

Do Chemicals Affect Your Jewelry?

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A woman loses a stone, she and her husband blame the retailer, the retailer blames the designer, the designer blames the manufacturers; the manufacturer looks for an answer. What causes breakage? Usually it’s stress or chemical corrosion from chlorine and bromine. Where does it originate? Hot tubs, swimming pools and laundry products.

Hoover & Strong conducted a controlled experiment to determine the effect of common chlorine and bromine products on jewelry settings. They used household bleach (heated and unheated), hot tub chlorine and bromine solutions and a chlorine free dishwashing detergent. They tested 14k and 18k nickel white settings, set and unset, rhodium plated and not plated, 14k palladium white gold and platinum settings.

As a result of these tests, they rated their products from the most chemical resistant to the least as follows:

1: platinum

2: rhodium plated 14k palladium white gold

3: 14k palladium white gold

4: rhodium plated 14k and 18k nickel white gold

5: 14k nickel white gold

Based on their testing, a consumer wearing a 14k nickel white gold setting could lose a stone or expect prong breakage as follows:

1) 5% chlorine bleach heated to 110F, prong failure occurred after 21 hours of exposure, only platinum and palladium white gold settings held their stones in this most severe test solution

2)5% chlorine bleach at room temperature- prong failure occurred after 120 hours of exposure

3) 5 parts per million chlorine using hot tub chemicals- prong failure after 312 hours or 156 days

4) 5parts per million bromine using hot tub chemicals- prong failure occurred after 384 hours or 192 days

5) household detergent- no visible effects on the settings

The settings soaked in the heated bleach suffered the most dramatic failure. The 14k nickel white gold was the first to fail in all solutions except household detergent. Testing bromine chemicals on yellow gold revealed that it does not affect white gold alloys as fast as yellow gold alloys. Bromine caused yellow gold to turn brown and make it brittle and prone to chemical corrosion cracking.

Lesson learned: Do not wear your jewelry in hot tubs or swimming pools. Take your jewelry off when using cleaning products and never ever clean rings with bleach!

Bring your jewelry into Carreras for proper cleaning.

METAL ALLOYS, What makes up Metals

June 12, 2013 6:55 pm 1 Comment

Yellow Gold contains Gold, Silver, Copper, Zinc

Pink Gold contains the same metals as yellow gold, but has a higher percentage of copper that gives it the pink or rose hue.

Green Gold also contains the same metals as yellow gold, but a higher percentage of silver gives it a green look.

22k Gold has the 24k look but is made harder for jewelry and dental use by adding 8.3% alloy

24k Gold is a very soft and malleable metal in its pure form. It can be made slightly harder by drawing or rolling the metal.

White Gold contains gold, copper, nickel, and zinc. Most alloys use nickel as the whitening agent. The metals are whiter than palladium white golds but are not as malleable

Palladium White Gold (14k & 18k) are superior to white golds alloyed with nickel. The palladium gives the white gold a slightly grayer color than nickel white gold.

Pure Platinum is very malleable. For jewelry use, 10% iridium is added as a hardener.

Carreras Jewelers - Richmond, VA

Author Archives: carreradmin

METAL ALLOYS, What makes up Metals

Why Jewelry sometimes Blackens the Skin or Clothing

Do Chemicals Affect Your Jewelry?

METAL ALLOYS, What makes up Metals

Carreras Jewelers - Richmond, VA

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