The mineral pyrite has long been called fool's gold, its metallic yellow crystals tricking miners into thinking they'd struck real gold. It is not without its uses – the compound creates sparks when hit with steel which can be used to start a fire – but it has always been seen as worthless next to its coveted cousin.
Fool's gold may boast immense resemblance to gold but doesn't have the properties of gold. It's shiny, beautiful, and even glitters when exposed to direct light. But unlike real gold, it's not shiny when not in direct light.
It is a lustrous mineral, meaning that it reflects light. When it is pulverized into a fine powder or dragged across a surface to create a streak, it appears greenish-black in color. This property of pyrite can be used to distinguish it from gold, which retains its yellow color even when pulverized or streaked.
Pyrite has a cubic structure; gold does not. Take a magnet with you. Iron pyrite will stick to the magnet because of its high iron content; gold will not. You can also use a drop of nitric acid to test your specimen.
Pyrite hand specimens are usually straightforward to recognise. The mineral is always brassy yellow in colour, has a metallic sheen, and has a high specific gravity. Its streak is black, frequently with a tinge of green, and it is more challenging than other yellow metallic minerals.
Pyrite is not magnetic. Some related minerals are, but only weakly, not as strong as iron, so the test will likely fail anyway. Magnetism is not an inherent property of an element, but that of a compound.
"Fool's gold" is a common nickname for pyrite. Pyrite received that nickname because it is worth virtually nothing, but has an appearance that "fools" people into believing that it is gold.
Detailed Description. Pyrrhotite is an iron sulfide mineral related to iron pyrite, which is one of the minerals known as Fool's Gold. Pyrrhotite, although not one of the Fool's Gold minerals, is sometimes called magnetic pyrite as it is weakly magnetic.
Whether in crystal or massive form, pyrite has a metallic luster. However, because the mineral does react chemically in air, it often has a dull or tarnished appearance.
Place your jewelry on a table or hold it in your hand, pour some white vinegar on the metal directly (a dropper can also be used) if the metal of the jewelry changes its color, it is not pure gold and if it keeps shining then you have real gold in your hand.
Perform a Streak Test
When rubbed against a streak plate (unglazed ceramic tile) minerals will leave a distinct color streak behind which can aid in the identification process. Gold leaves a distinct yellow streak, whereas pyrite leaves a rather ugly greenish-black streak.
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.
If left in a damp environment for even a short amount of time, it will break down quickly. However, that's just another useful trait of the mineral.
During World War II it was mined to produce sulfuric acid, an industrial chemical. Today, it is used in car batteries, appliances, jewelry, and machinery. Although fool's gold can be a disappointing find, it is often discovered near sources of copper and gold .
Pyrite is hard enough to scratch some metals but is brittle and breaks up easily when struck with a hammer. Gold is soft and malleable and can be pressed into very thin sheets.
Human teeth are harder than gold but softer than pyrite, according to the Mohs Hardness Scale, which categorizes how easily minerals scratch. This means a quick gnaw to real gold would actually leave an indentation. A hard chew of pyrite, meanwhile, might damage your teeth.
Your pyrite samples do not conduct electricity, so they are not seen by metal detectors. It's normal that pyrite is not an electrical conductor. A few minerals do conduct electricity and they show up well on a metal detector, even though they are not metals.
A visual inspection will at best only give an indication of the likelihood of pyrite. The sample of the backfill is sent to an approved pyrite testing company to be chemically tested. This pyrite test will conclusively show the pyrite levels present under the floors.
Chalcopyrite can be confused with pyrite, which is fools gold. However, pyrite will scratch glass, but chalcopyrite will scratch a penny, but will not scratch glass. Chromite is also metallic, although it is not often shiny. It is iron black in color, and sometimes is brownish black.
Pyrite is found in a wide variety of geological settings, from igneous, sedimentary and metamorphic rock to hydrothermal mineral deposits, as well as in coal beds and as a replacement mineral in fossils.
It can take up to ten years for the first signs of pyrite damage to show. Studies have shown that pyrite in backfill can take upwards of 30-40 years to swell where no more expansion can be expected and backfill will become stable.