Press a metal point into the grain. The U.S. Geological Survey says real gold “will gouge or indent like soft lead,” while pyrite, chalcopyrite and weathered mica “will flake, powder, or crumble.” A streak on unglazed porcelain confirms it: gold leaves a golden yellow streak, pyrite and chalcopyrite leave a dark green to black streak, and common micas leave a white one.

This guide is desk research from the USGS, the Utah Geological Survey and a BLM and Forest Service panning booklet. It is not a lab assay. For heavy grains you cannot place, the booklet’s advice is to keep them and have a geologist or miner identify them.

The three minerals most often mistaken for gold

The USGS names three. Pyrite is “the most common mineral mistaken for gold.” Chalcopyrite “may also appear gold-like,” and weathered mica “can mimic gold as well.” The BLM and Forest Service booklet adds that pyrite and mica “can occur with gold,” so finding them is not a bad sign about a creek.

Gold, pyrite, chalcopyrite and mica side by side

Test Gold Pyrite Chalcopyrite Weathered mica
Color Golden to silvery yellow Pale to medium brassy yellow; may tarnish Very brassy yellow; bronze or iridescent tarnish Light yellow to bronzy
Shape Nuggets, flakes, sheets, grains; crystals very rare Cubes, octahedrons, pyritohedrons; striated faces Not described in these sources Platy
Metal point Gouges or dents like soft lead Flakes, powders or crumbles Flakes, powders or crumbles Flakes, powders or crumbles
Pocket knife Can be cut Cannot be scratched Can be scratched Not described in these sources
Streak on unglazed porcelain Golden yellow Dark green to black Dark green to black White

Sources: USGS (metal point and streak), Utah Geological Survey (color, shape, knife), BLM and Forest Service booklet (mica color and shape).

Checks to do in order

Start with the checks that do not damage the find.

  1. Look at color and shape. The Utah Geological Survey says both minerals have a brilliant metallic luster but in different yellows: gold is “golden to silvery yellow,” pyrite “a pale to medium brassy yellow that sometimes tarnishes.” Pyrite often forms cubes or twelve-faced pyritohedrons, frequently with parallel lines on the faces. Gold usually comes as nuggets, flakes, sheets and shapeless grains; small gold crystals are “very rare.”
  2. Watch how it behaves in the pan. Gold is heavy. The BLM and Forest Service booklet gives its specific gravity as 19.3, “more than 19 times heavier than an equal volume of water,” and describes mica as lightweight. The USGS puts gold as it usually occurs in deposits at a density of 16 to 18, against about 2.5 for the waste rock around it. A flake that stays put while sand washes off is a better candidate than one that moves with the sand.
  3. Use a magnifier. The booklet’s equipment list includes a magnifying lens of at least 10X “to identify minerals.” Up close, the platy look of mica and the crystal faces of pyrite are easier to see.
  4. Press it with a metal point. This is the USGS test: gold dents, the look-alikes break up.
  5. Streak it. Scrape the grain across a piece of unglazed porcelain and compare the color of the line it leaves with the table above.
  6. Knife, hammer or smell, if you can spare the sample. The Utah Geological Survey says gold can be cut with a pocket knife and pyrite cannot, though chalcopyrite can. Struck with a steel hammer, gold “will flatten or change shape without breaking” while pyrite “will give off sparks.” Rubbed hard, pyrite gives off a sulfurous smell like rotten eggs; gold has no odor.

Why gold behaves differently

Gold is soft and workable. The USGS says pure gold “has about the hardness of a penny” and is “the most malleable and ductile of metals.” The booklet gives an average hardness of 2.8 on a 1-to-10 scale and notes that alloyed gold is harder. That softness is why gold dents under a metal point instead of crumbling.

Color varies, too. The booklet says gold’s yellow “turns paler as its silver content increases,” and the USGS says mixtures with other metals can shift its hue from silver-white to green and orange-red. Pale gold is still gold; go by the physical tests, not color alone.

Tiny flakes and flour gold

Very fine gold can fool you in the other direction. The booklet says flour gold “has been flattened to a few microns thickness and will float on water,” so a speck riding the surface of your pan is not automatically mica. It also says rough, nugget-like gold is near its source, while flat, smooth gold “has traveled some distance from its point of origin.”

The dark grains left at the end of panning are a separate question. The booklet says black sands may include magnetite, garnet, scheelite, zircon, cassiterite and platinum, and the USGS says magnetite is the most common. They are heavy like gold but are not gold.

Where this fits in panning

These checks matter most at the end of a pan, when only heavy concentrates remain; how to pan for gold covers the steps that get you there. If you are still choosing equipment, the gold panning kits and pans guide compares pans with fine-gold finishing surfaces, and the sluice box guide covers the step before the pan. Metal detector users working gold ground will also run into black sand and hot rocks; see what ground mineralization means for your settings .

FAQ

What is the easiest way to tell gold from pyrite?

Press a metal point into it. The USGS says gold gouges or indents like soft lead, while pyrite flakes, powders or crumbles. On unglazed porcelain, gold leaves a golden yellow streak and pyrite a dark green to black one.

Can mica look like gold in a gold pan?

Yes. The USGS says weathered mica can mimic gold. The BLM and Forest Service booklet describes mica as light yellow to bronzy, lightweight and platy, and common micas leave a white streak.

Does real gold tarnish?

The BLM and Forest Service booklet says gold does not tarnish when exposed to air. The Utah Geological Survey notes that pyrite sometimes tarnishes.

Sources