Identifying Non-Precious Metals
Metals are identified by examining numerals qualities, including appearance (color, shine, signs of aging), weight, magnification (drawn to magnet or not), use (your bicycle spokes won’t be made out of sterling silver) and hardness. Metal is often easy to identify. It can be more difficult with the metal is a small piece, such as when an embedded part of a larger ornate object.
What can further make make things harder is there are alloys, meaning mixtures of different and varying percentage of metals. Steel, for example, comes in varying percentages of different metals giving it different tone, hardness and magneticism. Gold is almost 100% gold . . . Someone might call something a ‘copper alloy’ meaning the metal is copper metal a smaller percentage of something else. Common alloys names include bronze, steel and brass.
For the purposes of collectors, it’s rarely important to determine the exact percentages of non-precious metal but determine a general label. Calling something an aluminum alloy or an iron alloy is usually good enough. Collectors often just want a good label. Now, if it’s silver or gold, then details are more important. Precious metals (silver, gold and platinum) are covered in an other.
Some metals are attracted to a magnet and some are not. The magnet is a good aid, though not a definitive test, in identifying metals. Metals are usually magnetic because they contain iron, though nickel is magnetic despite having no iron.
Magnetic metals include iron, nickel, cobalt and most of their alloys. Some forms of steel are magnetic, while others are not.
Non magnetic metals include aluminium, copper, lead, tin, titanium and zinc, and alloys such as brass and bronze. Precious metals such as gold and silver are not magnetic. Platinum is not magnetic, but, depending on what other metals is aligned with, can be magnetic in jewelry.
Mohs scale of hardness. The mohs scale of hardness is helpful in identifying metals, and this is a simple test to do. The hardness of a material is ranked on a 1 to 10 scale, with 10 being hardes and 1 being softest. Obviously, you want to take care not to scratch valuable antiques. It’s best to do the hardness test on an out sight place, like the bottom.
The following looks at the most common metals and allows in alphabbeti order.
Aluminum is fairly easy to identify as it is a silvery white color and is very light and bendable. It does not tarnish or rust so always remains its silver white color. It is commonly and widely used, but is not strong. It’s been used on toys, pins and many inexpesnive items It’s mohs hardness is 2.5-3 (about the same as gold) and it is not magnetic.
Brass (will be added later)
Bronze usually is an an alloy of copper and tin, but architectural bronze actually has a small amount of lead in it. Bronze has a dark coppery color and gets a green oxide over a period of time. Because bronze is an alloy densities vary. Bronze vibrates like a bell when hit. It’s Mohs is 3
Chromium is easy to identify because it is a very, very shiny and bright silver color and forms a clear oxide over time which means it rarely rusts or corrods. Things are rarely made of pure chromium but lots of things are coated with it to make it shiny and not rust. Chromium’s mohs is 8.5 which is very hard.
Copper is made into many alloys including brass and bronze. Copper is light red in color and gets a green oxide over time. Copper is not magnetc. Copper, like brass, also vibrates like a bell when hit. It has a mohns of 2-1/2 to 3.
Iron s a dull grey when unpolished and can rust to a reddish color. It is also used in a lot of alloys invlufinhsteel. Iron is heavy, and has a mohs of 6-7.
Lead is a dull grey when unpolished but shinier when polished. Lead is not magnetic Leads is extremely heavy, but not hard. It has a mohs of 4.
Magnesium has a grey color and develops an oxide that dulls the color. Magnesium is extremely flammable in powder or thin strips. Magnesium burns very brightly and hot and is very hard to put outs, even with water. Magnesium can also burn without oxygen Magnesium is very ligh . Because magnesium is so light it is used in engine blocks in cars, and because it burns so brightly it is used in weapons and fireworks It is soft wiith a Mohs of 2, mwaning it can be scratched by glass..
Steel Metal is used for wide variety of reasons and comes in a variety forms. It ranges in hardness from about 5 to 8. Some is magnetic and some is not. Hallmarks often identify it as steel. Old steel kitchen utensils are sometimes misidentified as silver.
Nickel is shiny silver when polished and is darker unpolished. Nickel is one of the few metals that is not an iron alloy that is magnetic. Nickel has a mohs of 4. Todays nickel coins are not made out of nickel.
Tin is silvery grey in color when polished and darker when unpolished. Tin has a mohs 1.4
Titanium is a silvery grey metal metal when unpolished and darker when unpolished. Titanium mohs 6
Zinc is naturally dull grey and is hard to polish. Zinc naturally rusts or galvanization. Because of its low cost zinc is the main metal in us pennies. Zinc’s mohs hardness 2.5 which is soft.