During the formation of Earth, molten iron sank to its center to make the core, which took with it the vast majority of the planet’s precious metals like gold and platinum. In fact, there are enough precious metals in the core to cover the entire surface of Earth with a four-meter-thick layer. These precious metals are popular to use in jewelry. ISO 22764:2020—Jewelry And Precious Metals – Fineness Of Solders Used With Precious Metal Jewelry Alloys provides specifications for the precious metal content for use in the production of jewelry.
How Much Gold is Earth’s Core and Ocean?
Earth’s core is a solid ball of iron and nickel. It is located approximately 1,800 miles beneath the planet’s surface. This depth is far beyond the reach of any current mining technology. As a result, mining Earth’s core, which is believed to contain vast amounts of gold, is not accessible. From using seismic waves to study the, scientists have estimated that the earth’s core contains around 1.6 quadrillion tons of gold, which is about 16 times more than the total amount of gold mined in human history.
What Is ISO 22764?
ISO 22764:2020 specifies the precious metal content in solders suitable for use in the production of jewelry made of precious metal alloys. Precious metal in this standard refers to platinum, gold, palladium and silver in the pure state and their alloys; precious metal alloy refers to solid mixture of a precious metal with one or more other metals made by melting or an electrochemical technique. ISO 22764:2020 specifies that the solder, an alloy used to join metal parts, should not decrease the measured mean fineness below the declared fineness.
Metals Used in Jewelry Making
Jewelry is usually made with precious metals like gold, platinum, and silver:
Gold is a dense, malleable precious metal that is bright yellow in color and can be polished to a high luster. In its pure form, 24 karat, it is extremely soft and ductile—making it somewhat useless for wearing in jewelry. Gold is commonly mixed with other metals or alloys like silver, copper, and zinc, making it more durable, harder, stronger, and long-lasting. Mixing gold with alloys also allows jewelers to create a wide range of color variations and working properties. In an attempt to achieve the best balance between the strength of alloys and the valuable and desirable properties of gold, three different karat gold combinations have become standard: 18 karat (75% gold and 25% alloy), 14 karat (58.3% gold and 41.7% alloy), and 10 karat (41.7% gold and 58.3% alloy). White gold alloys, mixed mainly with white metals like nickel, are typically stronger than yellow gold alloys, which are usually mixed with yellow metals like copper and silver.
Platinum is a dense, malleable, and strong metal that is white in color with cool undertones. It is almost always used in its purest form in 95% of jewelry. Platinum is substantial in weight; in the same volume, it weighs about twice the weight of 14 karat gold and is 25% heavier than 18 karat gold. For example, a ring in platinum will weight almost 60% more than the same ring in 14 karat gold.
Palladium is a member of the platinum metal group and is a soft, silvery-white color with slightly gray undertones, extremely durable, and unaffected by elements in the air that make other metals tarnish. This metal group includes platinum, ruthenium, osmium, iridium, and rhodium. These metals. It is used in an almost pure form in 95% of jewelry and 5% of other platinum group metals such as iridium and ruthenium. Palladium is more difficult to work with than platinum or gold, and it weighs much less.
Although silver is classified as a precious metal, it is a fraction of the value of gold and platinum. Pure silver, silvery-white in color, is far too soft to use for jewelry manufacturing, so it is also alloyed to improve its properties. Silver has a predominant quality known as “Sterling Silver,” and for an item to be marked as sterling, it must contain a minimum of 92.5% pure silver alloyed with 7.6% copper. Silver is the whitest of metals, has the highest reflectivity, and is the most lustrous. The main problem with sterling silver is that it is prone to tarnish.
ISO 22764:2020—Jewelry And Precious Metals – Fineness Of Solders Used With Precious Metal Jewelry Alloys is available on the ANSI Webstore