What’s even more incredible are historic coins like the St. Gaudens or British Sovereign and the level of detail inscribed on the coin before modern minting technologies were invented.
Of course, today’s machines are much more advanced and efficient. When the first U.S. Mint opened in Philadelphia in 1792, the press was powered by horses and oxen. Today’s processes are slightly more advanced, but one thing that has remained constant throughout is the purity and value of precious metals.
Continue reading to learn more about the amazing process used to mint gold and silver coins we enjoy collecting, investing in, or giving to family and friends as gifts.
Step One: Sourcing and Refining
The first step is “sourcing”. One method to acquire metals is mining, of course, but recycling precious metals from old jewelry, unwanted bullion, discarded electronics, and ornaments is increasingly becoming a go-to source for raw precious metals. After the raw metal is identified, it requires further refining to remove other impurities and ensure it is .999 or .9999 pure.
Step Two: Melting and Pouring
The raw, refined gold or silver must undergo further preparation before being ready for coining. Metals are prepared for minting by heating them past their melting point (approx. 1950oF for gold and 1765oF for silver) and then pouring them into a tube to create what is referred to as a “billet”. One silver billet weighs around 810 ounces.
Check out this quick animation of pouring molten gold into a billet:
Step Three: Annealing and Extruding
The metal in a billet is very hard, especially silver, so it needs softening before it can be pressed. This softening process is called “annealing” and typically involves reheating the billet. Once the gold or silver is more malleable, it is then fed through an extruder which turns the cylindrical shape into long, thin strips of gold or silver. These strips are carefully inspected to ensure proper thickness and no scratches.
Step Four: Punch Blanks and Cleaning
After these long, thin sheets of metal emerge from the extruder, they are cut into more manageable lengths and fed through a press. The round press “punches” what become the coins into 1-ounce rounds (or whatever the desired weight is). The rounds, or “planchets”, then go through a cleaning process which typically uses a vibrating machine containing small ball bearings in a warm soap and water solution. This process helps remove any blemishes or rough spots that are sometimes present.
Step Five: Strike It, Strike It Good!!
Once polished, blanks are then taken to a press for striking. The blank is placed in a round “collar” located in a minting press between the top and bottom dies. When the press comes together, the impact causes the metal in the blank to “flow” into the die’s recessed areas, giving the coin its special appearance.
Step Six: Additional Finishing, Prepare for Shipment
After final striking, coins are once again polished and undergo additional finishing if the design requires it. The coins are then packaged and shipped to retailers like Provident Metals. American Silver Eagles, for example, are packaged in rolls containing 20 coins each. One Monster Box equals 25 rolls with 20, 1-ounce coins in each roll.
Of course, this brief summary of the minting process just barely scratches the surface. Before the minting even commences, the design and dies for the coin have to be developed. This process is even more elaborate, requiring special engraving skills and is probably the most time consuming part of making a coin.
We invite you to continue browsing our blog and knowledge center to learn more about the minting of popular gold and silver coins. And, if you’re ready to invest in silver coins or other precious metals, we invite you to browse our online store with secure online ordering today!