If you have ever been panning or prospecting for gold, you know the excitement a prospector can experience upon finding a golden piece of metal. However, many prospectors are easily deceived by Pyrite, also called Fool’s Gold, a virtually worthless element.
To avoid Fool’s Gold (Pyrite) when panning, prospectors should know that this differs from gold in shape, color, and smell. Some tests such as glitter, hardness, and streak tests can scientifically determine what metal you are dealing with. However, these could compromise your findings.
Let’s find out how to distinguish the two metals while panning.
Table of Contents
What Is Fool’s Gold?
If you are planning your next prospecting trip, you should keep in mind that Fool’s Gold – or Pyrite – is a standard metal that can be confused with gold. This metal’s nickname is Fool’s Gold because it could easily fool prospectors who are not familiar with the differences between the two substances.
Pyrite is an iron sulfide and the most common of the sulfide minerals. Unlike gold, it forms at both high and low temperatures. However, like gold veins, it is usually located in igneous (magmatic) rock, among other types. Its name derives from the term “pyr,” which in Greek means “fire” because it can be used to create sparks if rubbed against other hard materials.
At first sight – and in particular, when it comes under the form of nuggets – Pyrite can look like gold. However, some easily spottable differences enable a prospector to differentiate between the two.
Differences Between Gold and Pyrite
Shape
Generally, Pyrite is composed of several crystals, which give Fool’s Gold formations characteristic sharp edges. If a prospector can examine a piece of Pyrite close enough, he or she will notice small, sharp cubes dotting its surface. Oppositely, real gold boasts much smoother surfaces and edges that are round.
However, it is essential to notice that gold can change in appearance. This depends on how far away from the lode has been found and how much it was weathered. Indeed, pieces that have been separated from the lode more recently will look like coats (rough) specimens. Oppositely, gold nuggets and flakes that have been subjected to the force of natural elements for longer will be smoother and rounder.
Smell
This test might be challenging to perform if you need to differentiate between two small particles of Pyrite and gold. However, it is helpful to know that, being an Iron Sulfide, Pyrite will lightly smell of sulfur. Instead, gold is usually odorless.
In the case of small particles or when prospecting outdoors, smells can be easily confused. However, if you are not sure, bring the Pyrite back with you to a controlled environment, where you can person this test safely.
Color
Pyrite specimens always have a brass-yellow color and a metallic luster. Oppositely, gold nuggets and flakes have a yellow-golden color. Additionally, native gold is often alloyed with silver, which, if present in high quantities, will cause the gold to assume a paler yellow color tending to white.
Specific Gravity
The specific gravity of gold is 19.3. This value positions the metal among the ones with the highest specific gravity in streambed materials and soil. Only Platinum (21.45) and Tungsten (19.3) have higher specific gravity than gold. Even specimens that only contain gold alloys with other minerals and metals will have higher specific gravity than non-gold-containing particles.
Pyrite, instead, has a specific gravity of 4.95–5.10, depending on its composition. There are easy methods to calculate the specific gravity of the specimen you have retrieved.
Magnetism
Unlike other materials in the black sand concentrates you have at the bottom of your pan at the end of the panning process, gold is not magnetic. However, Pyrite is. So you can perform a preliminary test by bringing along a black sand magnet on your prospecting trip.
If you are used to separating the concentrates with a magnet, this will not be any different. If the gold-like specimen in your pan is Pyrite, it will remain attached to the magnet. Otherwise, you would have found gold.
Learn more about the visual differences between the two elements in the video below.
Tests
Some other tests can help you scientifically distinguish Fool’s Gold from real gold. These should be performed before deciding to sell the gold you found or to obtain an indication of its value.
Many prospectors opt to perform these tests in a controlled environment by using a piece of Pyrite and a piece of real gold. This is essential to notice what outcome each stone produces and what to expect on a prospecting trip.
A cautionary note: it is essential to notice that the tests below might compromise the specimen of gold you have found if not performed correctly. These are sometimes labeled as “destructive tests.” If you are not confident regarding implementing them, it is recommendable to get in touch with an expert.
Glitter Test
While not categorized as destructive, this test requires you to have an expert eye. Indeed, gold, unlike Pyrite, does not glitter. While it can shine and assume different bright colorations depending on other particles and metals on it, it will not glitter[1].
Pyrite, on the other hand, boasts a crystalline structure. This characteristic causes the light to refract and bounce on multiple surfaces, giving the specimen a glittery look. For better proofs, turn your specimen lights and notice how the light reacts to it.
Hardness Test
Gold is a much softer metal than other shiny rocks such as Pyrite or mica. Therefore, gold will bend or even dent if a prospector applies a small force on its surface. Instead, Pyrite might not bend, but it turns brittle quickly. In the past, prospectors would place a sample in their teeth and bite it to see whether they would leave a mark on the gold or if it would become brittle[2].
While this might be an effective way of proving whether a specimen is real gold or not, notice that any mark on it can decrease its value, especially if you are dealing with a piece of gold with a crystal habit. Alternatively, you could use the edge of a knife to add pressure to the piece. The marks – if there are any – left by this tool will be less noticeable.
Streak Test
Streak tests are the easiest ones to perform. The streaks left by metal or rocks are the marks visible by rubbing or scraping the metal on a “streak plate” (usually unglazed porcelain). The stripe that gold leaves behind is typically yellow or golden. Instead, Pyrite – due to the high content of iron in this agglomeration – will leave a green streak with black hues.
Just as seen before, this test can be harmful to the specimen, especially if you are testing a piece of real gold.
Acid Test
Using nitric acid to test a specimen is something that only an expert prospector should do without supervision. The principle behind this test is that nitric acid will not affect real gold, while it tends to dissolve the majority of the streambed materials a prospector deals with. Creating a nitric acid solution might require expertise and caution, but you can easily understand the nature of your specimen by emerging in it[3].
Conclusion
Finding a golden specimen in your pan after a long day of prospecting can be exciting. However, before jumping to conclusions, it is essential to perform the necessary tests to ensure that you are dealing with real gold. Looking at the specimen, smelling it, and weighing it can give you valid indications regarding its nature. However, prospectors can perform other tests to ensure its purity. Some of these tests can be destructive, and you will need to act with caution.