What is "Fool's Gold?"

Fool's Gold can be one of three minerals. The most common mineral mistaken for gold is pyrite. Chalcopyrite may also appear gold-like, and weathered mica can mimic gold as well. Compared to actual gold, these minerals will flake, powder or crumble when poked with a metal point, whereas gold will gouge or indent like soft lead. In addition, actual gold will leave a golden yellow streak when scraped on a piece of unglazed porcelain. Pyrite and Chalcopyrite will leave a dark green to black streak and the common micas will leave a white streak.

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Where can I find information about mineral commodities?

For statistical information about mineral commodities, visit the USGS Commodity Statistics and Information website. For locations outside the United States, the USGS International Minerals Statistics and Information website is the best starting point.

What is white gold?

White gold was originally developed to imitate platinum (a naturally white metal). White gold is usually an alloy containing about 75% gold and about 25% nickel and zinc. If stamped 18 karat , it would be 75% pure gold.

What is the meaning of the karat mark on gold jewelry?

The fineness of jewelry gold is stated as the number of parts in twenty-four that are gold. Thus, 24 karat gold is pure gold; 12 K would be an alloy that is half gold and half copper or other metals.

What is the difference between a rock and a mineral?

A mineral is a naturally occurring inorganic element or compound having an orderly internal structure and characteristic chemical composition, crystal form, and physical properties. Common minerals include quartz, feldspar, mica, amphibole, olivine, and calcite. A rock is an aggregate of one or more minerals, or a body of undifferentiated mineral...

What is sterling silver?

Sterling silver is the standard of quality for articles containing 92.5% silver and 7.5% copper (and/or other alloys).

How much silver has been found in the world?

Of the 1,740,000 metric tons of silver discovered to date, 55% is found in just four countries on earth. All the silver discovered thus far would fit in a cube 55 meters on a side. Learn more at the USGS commodity website for silver .

How much gold has been found in the world?

About 244,000 metric tons of gold has been discovered to date (187,000 metric tons historically produced plus current underground reserves of 57,000 metric tons). Most of that gold has come from just three countries: China, Australia, and South Africa. The United States ranked fourth in gold production in 2016. All of the gold discovered thus far...

How much copper has been found in the world?

To date, roughly 700 million metric tons of copper have been produced around the world. This would fit into a cube measuring about 430 meters on a side. Identified deposits contain an estimated 2.1 billion metric tons of additional copper, which brings the total amount of discovered copper to 2.8 billion metric tons. This would fit into a cube...

How large is a lifetime supply of minerals for the average person?

At today's level of consumption, the average newborn infant will need a lifetime supply of 800 pounds of lead, 750 pounds of zinc, 1,500 pounds of copper, 3,593 pounds of aluminum, 32,700 pounds of iron, 26,550 pounds of clays, 28,213 pounds of salt, and 1,238,101 pounds of stone, sand, gravel, and cement.

How many pounds of minerals are required by the average person in a year?

To maintain our standard of living, each person in the United States requires over 38,449 pounds of minerals each year: 9,426 pounds of stone 6,768 pounds of sand and gravel 655 pounds of cement 142 pounds of clays 338 pounds of salt 244 pounds of iron ore 195 pounds of phosphate rock 34 pounds of soda ash 28 pounds of aluminum 13 pounds of copper...

How do we extract minerals?

The primary methods used to extract minerals from the ground are: Underground mining Surface (open pit) mining Placer mining The location and shape of the deposit, strength of the rock, ore grade, mining costs, and current market price of the commodity are some of the determining factors for selecting which mining method to use. Higher-grade...

What minerals produce the colors in fireworks?

Mineral elements provide the color in fireworks. Barium produces bright greens; strontium yields deep reds; copper produces blues; and sodium yields yellow. Other colors can be made by mixing elements: strontium and sodium produce brilliant orange; titanium, zirconium, and magnesium alloys make silvery white; copper and strontium make lavender...
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Date published: May 22, 2018

Digital Gold Rush Depends on Traditional Gold

In 1849, the discovery of gold in California sparked one of the most famous gold rushes in history. Thousands trekked across mountainous terrain to seek the precious metal, with entire industries springing up around the rush. In fact, the desire to understand our mineral resource wealth that led to the creation of the U.S. Geological Survey was in part fueled by gold rushes like this one.

Date published: April 25, 2017

EarthWord–Placer

Whether you pan for gold or rare earths, you’ll get a lot of sand...and this EarthWord!

Date published: April 4, 2017

EarthWord–Rock vs. Mineral

Ever wondered what the difference between a rock and a mineral was? This EarthWord should cover it...

Date published: April 1, 2017

The Golden Rule on April Fools

Think you know which mineral Fool’s Gold is? You might be fooled...

Date published: May 6, 2016

EarthWord - Mother Lode

Happy Mother's Day from EarthWords!

Date published: February 15, 2016

EarthWord – Ore

The naturally occurring material from which a mineral or minerals of economic value can be extracted. Usually minerals, especially metals, are mined first in ore form, then refined later.

Filter Total Items: 11
Close up of Chalcopyrite
March 23, 2017

Chalcopyrite

Mineral: Chalcopyrite
Mineral Origin: Bingham Canyon, UT
Primary Commodity: Copper
Primary Commodity Uses: Copper is used primarily in electronics, mostly in building construction and industrial electronics.

Close up of Conglomerate (Gold Ore)
March 23, 2017

Conglomerate (Gold Ore)

Rock: Conglomerate (Gold Ore) Contains sediments of Precambrian age; contains about 8 grams of gold per ton of rock.
Mineral Origin: Witwatersrand formation, South Africa. The gold in the Witwatersrand Basin area was deposited in Archean river deltas having been washed down from surrounding gold-rich greenstone belts to the north and

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Close up of Chalcopyrite, Pentlandite, and Pyrrhotite
March 23, 2017

Chalcopyrite, Pentlandite, and Pyrrhotite

Mineral: Chalcopyrite, Pentlandite, Pyrrhotite
Mineral Origin: Creighton Mine, Sudbury, Ontario, Canada (Sample on loan from George J. Coakley)
Primary Commodity: Copper and nickel
Primary Commodity Uses: Copper is used primarily in electronics, mostly in building construction and industrial

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Image shows a sample of gold against a black background
December 31, 2016

Native Gold

A sample of native gold. Gold has been treasured since ancient times for its beauty and permanence.   Most of the gold that is fabricated today goes into the manufacture of jewelry, but it also performs critical functions in computers, communications equipment, spacecraft, jet aircraft engines, and a host of other products. Read more about gold

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Image shows a cubical sample of pyrite with a quartz crystal extending beneath it
December 31, 2016

Pyrite and Quartz

A sample of pyrite and quartz. Iron pyrite, also known as Fool's Gold due to its resemblance to gold, often occurs in quartz veins. Pyrite is an important source of sulfur dioxide, which is primarily used to create sulfuric acid, an important industrial acid. In fact, consumption of sulfuric acid has been regarded as one of the best indexes of a nation's industrial

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Image shows gold-bearing veins of quartz
May 6, 2016

Gold Veins

Gold-bearing quartz veins from the Blue Ribbon Mine, Alaska. Credit: AlaskaMining at English Wikipedia, CC BY 2.5, https://commons.wikimedia.org/w/index.php?curid=44555449

USGS
April 1, 2008

What is Fool's Gold?

Listen to hear the answer.

Image shows a macro image of biotite
November 30, 2000

A Sample of Biotite

A sample of biotite. 

Image shows black pans with gold grains
November 30, 2000

Gold Pans and Placer Gold

Gold Pans and Placer Gold - image by Max Flanery, California Geological Survey.

Image shows a scan of a grain of pyrite rimmed with stibnite, with varying levels of arsenic shown in a color gradient. Image pr
November 30, 2000

EMP Image of Pyrite

Image shows a scan of a grain of pyrite rimmed with stibnite, with varying levels of arsenic shown in a color gradient. Image produced by Erin Marsh, USGS.

Image: Hydraulic Gold Mining

Hydraulic Gold Mining

Hydraulic gold mining near Nevada City, Calif.