Precious Metals Resource Guide

Quite a few things have happened since the Bronze Age. There are now thousands of different grades and types of metal out there, and each is developed for specific applications. Each and every day, you come into contact with dozens of kinds of metal. Let’s walk through different classifications and uses for metals around the world.

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Table of Contents


  • Gold Alloys
  • Karat
  • Colored Gold


  • New Gold and Old Gold
  • Gold Solder


  • Gold Filled
  • Rolled Gold Plate
  • Gold Overlay Care


  • Tarnish


  • Sterling Silver
  • Mexican Silver
  • Coin Silver
  • Britannia Silver
  • Other Silver Alloys


  • Electrum
  • Niello
  • Non-Silver Jewelry Metals with Silver Names
  • A Quick Note On Quicksilver


  • Platinum Jewelry Use
  • Platinum Alloys


  • You May Be Sitting On Treasure

Following the bronze age, there were loads of metal discoveries dating from roughly 3300 BC to 1200 BC–utilized for various reasons. In the later periods, these developed further into different types. However, modern scientists continue to develop these further as they have discovered new elements. Major companies are now using these metals in thousands of applications across the world.

When it comes to precious metals, however, there are a few key players who have stood the test of time.

What are the Noble Metals?

From a chemical standpoint, noble metals resist corrosion and oxidation when exposed to moist air. Additionally, they possess varying degrees of resistance to acids. The noble metals list includes:


In addition to their noble metal properties, silver, platinum, and gold also possess the following characteristics:

  • They occur worldwide, but not in high enough quantities to lower the value
  • They are considered precious metals and have all been used as currency
  • Different cultures, historically and currently, consider these metals sensuous, beautiful, and glamorous–increasing their appeal
  • These metals possess malleability–making them practical options for jewelry, coins, dental fixtures, and more.

For all of these reasons, the silver, gold, and platinum trio continue to be extremely popular for any valuable metal items. 

Gold has been long coveted for its beauty, but it also possesses physical properties that have captivated humanity in a different way. Because gold has great items prefer it to other metals. In fact, just one ounce of gold can be stretched into a thread lasting more than 50 miles long. When properly cared for, gold can last forever, making it a prized metal to designers and consumers. It doesn’t corrode or oxidize and only a small handful of rare acids or hot chlorine bleach can cause damage to it.

Gold has survived and witnessed many transformations, and it’s safe to say it may continue to do so. Gold can be reused and reshaped by melting down old gold objects and forming the gold into new items or pieces. For example, broken pieces of jewelry and old coins can be melted down and reused to make new, beautiful gold jewelry.

Gold Alloys

Regardless of all gold’s desirable properties, it does have one drawback: softness. This means that it can wear out easily–this quality is different from mineralogical/gemological measurements of hardness as resistance to scratching. However, mixing gold and other metals can create gold alloys that are more durable, stronger, and better suited for certain uses. Certain items are made from pure gold, but when it comes to jewelry, these pieces show wear and dent so readily that most people wouldn’t wear pure gold jewelry on a regular basis.

Metals commonly mixed with gold to create alloys include copper, nickel, zinc, iron, tin, cadmium, manganese, titanium, and silver. In addition to enhancing gold’s strength, alloying also changes some of its properties. For example, some gold alloys can cause allergic reactions or stain skin. These reactions aren’t caused by the gold itself, but instead the alloyed metals.


When discussing gold alloys, the term karat is used to indicate the purity of the gold–not to be confused with carat–a unit of measurement used for gemstone weight. Pure gold, containing no other metals, is called 24-karat gold. Therefore, a 50/50 alloy is half pure gold and half the other metal or metals would be 12-karat gold. Alloys utilized in jewelry making range from 8-karat gold–approximately 33% pure gold, up to 24-karat gold. Pieces need to be hallmarked and stamped according to purity.

A somewhat new alloy that is gaining popularity in the jewelry scene is the gold titanium alloy. It consists of 99% gold and 1% titanium. This permits the alloy to remain nearly all gold in its color and composition while still providing improved durability.

Karat Parts Gold Percent Gold Other Marks
24 24/24 100% 1000
18 18/24 75% 740
14 14/24 58.33% 585
12 12/24 50% 500
10 10/24 41.66% 416
Gold Color Alloys
White 10% to 20% nickel, plus copper, tin, sometimes platinum or manganese
Green Silver, sometimes cadmium, and zinc
Red or Pink Copper
Yellow Silver and copper
Blue Iron

Colored Gold

The color of gold will change when it is alloyed. For instance, mixing gold with copper will create a darker yellow color. Mixing in nickel plus copper, zinc, platinum, or manganese will produce white gold. Most of the time, white gold does not contain silver–silver softens gold and gives it a slight green tint. Other gold alloy color variations include blue and red.

Gold Labeling

In the United States, there are strict laws governing gold purity labeling. In order to be labeled as a specific karat, a solid item needs to be within three parts per thousand of the karat marking. Any item containing solder but be within seven parts per thousand. Any pieces that fail to meet these criteria will receive a lower karat designation.

When labeling gold items for sale, vendors cannot legally say an item is “solid gold” unless it is truly 24-karat. Any other reference of an item’s gold containment must designate its karat.

New Gold vs Old Gold

“New gold” does not mean that the gold was recently mined. Instead, it means the gold has been carefully refined to meet current gold standards. On the other hand, “old gold” is produced by melting down old coins, jewelry, and other gold items. Depending on the amount of solder the original pieces contained, old gold could have a slightly lower karat weight compared to the original gold.

The impurities of old gold items can cause a variety of headaches during the casting process–including bubbles. Therefore, jewelers typically send old gold to a refiner rather than melting and recasting a new object at their own workshop.

Gold Solder

Jewelers utilize gold solder to join together pieces of gold. Because solder needs to have a lower melting point than the pieces it joins, it is mixed with metals that have lower melting points than gold. Gold solder is sold exclusively on its color and not on its gold content. This does not pose any problems for the jewelry or item’s current owner, however, melting down the piece with its solder, later on, will reduce the gold’s karat.

Gold Overlay Pieces

With solid gold selling for a high price, some makers of jewelry, dishware, and other items look for alternative ways to deliver the look and feel of gold to their customers at a lower cost. One common tactic involves coating pieces made of less expensive metals with thin coats of gold. These items are known as gold overlay pieces.

There are two different overlaying methods:

  • Gold-filled
  • Gold-plated




Pieces that are “gold filled” have a minimum of 5% gold applied to their base metal. The karat and relative quantity of the overlaid gold determine their classification. For example, if a piece is stamped “1/20 14K GF” that means it has a 14-karat gold layer making up 1/20th of its weight.


At various points throughout history, people and cultures have valued silver more highly than gold. It has a long history of being used as an exchange medium as well as for jewelry and items such as silverware–but more recently silver has found many new uses. Today, it can be found in electronics, medicine, appliances, clothing, and more.


The beloved noble metal silver does have its drawbacks, though. The most notable is that it tarnishes. The term “tarnish” describes a layer of corrosion that forms over some metals–silver included–when they experience chemical reactions. The chemical reaction that causes silver to tarnish needs a compound called hydrogen sulfide. Because this compound can occur out in our air, silver pieces left exposed will typically tarnish over time.

Storing your silver items in protective containers or pouches will reduce the amount of tarnish they experience. This will mean less time spent removing tarnish from your silver items and jewelry. Silver does require more care than some other precious metals, however, there are plenty of polishing options–from do-it-yourself home methods to commercially available. Don’t allow tarnish to damage your silver items.

Silver Alloys

Similar to gold, pure silver is rather soft and easily damaged. Therefore, silver item casters and jewelry makers often alloy silver with stronger metals to improve durability. With silver alloys, they are able to create strong, beautiful silver pieces.

Silver Alloys

Similar to gold, pure silver is rather soft and easily damaged. Therefore, silver item casters and jewelry makers often alloy silver with stronger metals to improve durability. With silver alloys, they are able to create strong, beautiful silver pieces.

Silver Jewelry Use

Jewelry makers will stamp silver pieces with a code for the alloy used. For example, 925 indicates sterling silver, 958 indicates Britannia silver, and so on. If you’re shopping for silver jewelry, inspect the piece carefully for its alloy stamp.

Although jewelers use sterling silver more frequently than any other alloy for silver jewelry, there are other silver jewelry metals worth mentioning.



Electrum is a naturally occurring gold and silver alloy that enjoyed great popularity in Ancient Egypt. Because of its natural origins, the ratio of gold to silver varies with each individual piece.


You’ll often see this black mixture of copper, lead, and silver utilized like an enamel. Similar to electrum, the Ancient Egyptians often utilized this material. Over time, niello techniques made their way throughout Europe and Asia.

Non-Silver Jewelry Metals with Silver Names

All the silver alloys previously mentioned contain at least some silver. However, some metal names can be misleading.

The alloys referred to as nickel silver, or German silver, for example, contain zinc, nickel, and other metals. They do resemble silver in their coloring, hence the name, but they don’t actually contain any silver.

Quick Note on Quicksilver

“Quicksilver” is actually an ancient labeling term for the metal mercury. Despite mercury resembling liquid silver or “living silver,” it does not contain any silver. Mercury/Quicksilver has no purpose as a jewelry metal because of its liquid state and toxicity at normal temperatures.

More rare and expensive than gold, platinum has unmatched durability and holding power. It will not tarnish. These qualities make platinum one of the most premium and highly coveted jewelry metals. Especially for engagement and wedding rings.

Platinum also has a variety of industrial applications. For example, it’s used to make catalytic converters.

Platinum Alloys

It may come as a surprise, but the term “platinum” actually refers to a group of metals. In addition to platinum itself:


While platinum is the most abundant, all of these metals with the exception of osmium, have jewelry applications.

Rhodium is often used as a non-tarnishing plating for silver, white gold, and other platinum group jewelry metals. Iridium and palladium are frequently alloyed with other metals or even used alone to make jewelry pieces.

The most popular platinum alloys include 95% platinum and 5% ruthenium, or 90% platinum and 10% iridium. Of the two, the platinum-ruthenium alloy makes for a harder and stronger alloy.

Honorable mention to the platinum-gold alloy–the most wear-resistant metal in the world.

Precious Metal Coins

Coins made of precious metals (silver, gold, platinum, palladium, and rhodium) are officially minted for the purpose of investment. Bullion value is determined by the weight and type of metal traded on commodity markets.

The coins we purchase include but are not limited to American Eagles, Austrian Philharmonics, Canadian Maple Leaves, Australian Golden Nuggets, South African Krugerrands, Mexican Pesos and Onzas, French and Swiss Francs, Great Britain Crowns and Sovereigns, Isle of Man Crowns, Italian Lire, and Chinese Pandas.

You May Be Sitting on Treasure

At the Gold Guys, we believe the best treasure is already above ground. It’s not about mining for new precious metals; it’s about recycling old and unwanted items.

The value is in the precious metal content of your pieces. When your items are refined, the precious metals are recycled and transformed into small beads that are then purchased and used by the coin makers, the jewelry industry, and Mints to make new coins and to craft new items.