You can sort out most rocks at home with five tests: streak, hardness, weight, a magnet and a close look at the surface. Most rocks people find in yards, creeks and fields, such as granite, basalt, sandstone, limestone and quartz pebbles, have no resale value as of late 2026, and that is the honest normal result. The few finds that are worth money fall into clear groups: native gold, which sells close to its metal value of about $4,000 an ounce; real meteorites, which sell for about $1-20 a gram for common stony and iron types; good mineral specimens such as sharp pyrite or quartz crystals at about $1-30 for most pieces; and collectible stones like agate, geodes, petrified wood and fossils, which have their own markets.
The tests below are cheap and take minutes. They will not prove that a rock is valuable, but they will quickly tell you when it is not, which is most of the time, and they will tell you which of the few interesting groups a rock belongs in, so you know whom to ask next.
Quick answer
- Most found rocks are common and have no resale value. That is true of nearly everything in a yard or driveway.
- Gold: soft, heavy, golden streak, bends instead of shattering. Pyrite: hard, brittle, greenish-black streak, worth a few dollars.
- Meteorites: heavy, usually attracted to a magnet, thin black crust, no bubbles, no streak. Most suspected meteorites are slag, magnetite or hematite.
- Quartz crystals, pyrite and common minerals sell for about $1-30. Ordinary meteorites $1-20 a gram, iron meteorites $0.50-5 a gram.
How to identify a rock at home, step by step
You need an unglazed white porcelain tile (the back of a bathroom tile works), a steel nail or knife, a piece of glass, a copper coin, a strong magnet, a kitchen scale, a magnifier and a flashlight.
- Wash it and look. Rinse with water and a soft brush and dry it. Look at the color, the luster (metallic, glassy, waxy, dull), the grain size and whether you can see separate crystals, layers, bubbles or fossils. Look at a fresh broken surface if you have one, since the outside of a rock is often stained.
- Do the streak test. Rub the rock firmly across the back of the porcelain tile. The color of the powder line is more reliable than the color of the rock. Gold leaves a golden yellow streak. Pyrite and chalcopyrite leave a greenish-black streak. Hematite leaves a red-brown streak. Magnetite leaves a black streak. Most meteorites leave no streak or a faint gray one. Quartz and other hard minerals leave no streak because they are harder than the tile.
- Test hardness. The Mohs scale runs from 1 (talc) to 10 (diamond). A fingernail is about 2.5, a copper coin about 3, glass and a steel knife about 5.5, and quartz is 7. Try to scratch the rock with each in turn, and try to scratch glass with the rock. Quartz, agate, jasper and petrified wood scratch glass. Calcite and gold do not, and a knife scratches them. Pyrite at 6 to 6.5 barely scratches glass.
- Weigh it in your hand and on a scale. Density tells you a lot. Most common rocks and quartz weigh about 2.6 to 2.7 times as much as the same volume of water. Pyrite is about 5. Iron meteorites are about 7.5 to 8, and stony meteorites about 3.3 to 3.7. Gold is 19.3. To measure it, weigh the rock dry, then weigh it hanging in water from a thread; divide the dry weight by the weight loss.
- Try the magnet. Most meteorites contain iron-nickel metal and stick to a strong magnet, or at least pull it. So do magnetite, many slag pieces and some iron-rich basalts. Gold, pyrite, quartz and most ordinary rocks do not stick.
- Look at the surface closely. A meteorite usually has a thin black or brown crust, under a millimeter, sometimes with thumbprint-like dents (regmaglypts). It has no bubbles and no layers. Industrial slag is often glassy or bubbly, full of round holes. Sedimentary rocks show layers or sand grains. Fossils show shells, leaves or bone texture.
- Look for crystal shape. Six-sided points are quartz. Cubes with striations on the faces are pyrite. Purple quartz is amethyst. Blades, rhombs and stubby crystals point to calcite, barite and other minerals worth asking a club about.
- Note where you found it. A creek in a gold district, a known agate beach, a plowed field with chips of flint, a road built with slag: location narrows what a rock is likely to be more than anything else.
What is valuable and what is not
Values are for typical finds as of late 2026, from dealer prices, sold listings and metal spot. They assume the identification is correct.
| Find | How to recognize it | Typical value, as of late 2026 |
|---|---|---|
| Granite, basalt, sandstone, limestone, river cobbles | Common rock textures, no special features | No resale value |
| Quartz pebbles and white vein quartz | Milky white, scratches glass, no crystal faces | No resale value |
| Industrial slag | Glassy, bubbly, often heavy and magnetic | No resale value |
| Quartz crystal points | Clear six-sided points | About $1-30; large clear points more |
| Herkimer "diamonds" (New York) | Small, clear, double-pointed quartz | About $1-50 depending on size and clarity |
| Pyrite, loose or small clusters | Brassy cubes, greenish-black streak, brittle | About $2-30; fine Spanish cubes more |
| Hematite and magnetite | Heavy, black or silver, red-brown or black streak | About $0-10 |
| Native gold, small flakes and nuggets | Soft, golden streak, does not shatter | Close to metal value, about $4,000 per troy ounce; nice nuggets carry a premium |
| Ordinary stony meteorite (chondrite) | Heavy, magnetic, thin black crust, metal flecks inside | About $1-20 per gram at dealer retail; unclassified desert finds often under $1-2 a gram |
| Iron meteorite | Very heavy, strongly magnetic, rusty, no streak | About $0.50-5 per gram for common types |
| Agate | Translucent, banded, waxy | See agate value |
| Geode | Round, light for its size, hollow | See geode value |
| Petrified wood | Heavy stone with wood grain and rings | See our petrified wood value guide |
| Shark teeth and fossils | Tooth, shell, bone or leaf shapes | See our shark teeth value guide |
| Worked stone (points, grinding stones) | Flaked or ground by people | See arrowhead value and our grinding stone guide |
The first three rows cover almost everything people pick up and ask about. Rocks are a collector's hobby, and most of the pleasure is in finding and naming them; resale prices are low because the supply is endless. Gold and meteorites are where real money sits, and both are much rarer than hopeful finders expect.
A worked example
Say you find a heavy, dark, rusty rock in a field, about the size of a golf ball, and it sticks to a fridge magnet. That is the classic "is this a meteorite" find. Rub it on the back of a tile: if it leaves a black streak, it is most likely magnetite; a red-brown streak means hematite. Look at it under a magnifier: round holes and a glassy look mean slag from old smelting or a railroad bed. If it leaves no streak, has no holes, has a thin dark crust and, when you grind a small corner flat on a file or sandpaper, shows bright metal flecks, it is a candidate meteorite. Only then is it worth sending a photo and description to a university meteorite lab. The odds are low: most "meteorites" sent to labs turn out to be meteorwrongs. A real 60 gram ordinary chondrite might retail for roughly $60-600, a dealer buying it would pay well under that, and a new find that has been classified by a lab is worth more than an unclassified one.
Gold versus pyrite and mica
Pyrite is called fool's gold for good reason. The tests settle it quickly:
| Test | Gold | Pyrite | Mica flakes |
|---|---|---|---|
| Streak | Golden yellow | Greenish-black | Whitish or none |
| Hardness | Soft; a pin dents it | Hard; scratches glass a little | Soft, flakes apart |
| Under a hammer or knife | Bends and flattens | Shatters into powder | Splits into sheets |
| Color in shade | Stays golden | Turns brassy or pale | Shifts with angle, sparkly |
| Weight | Extremely heavy | Moderately heavy | Light |
| Crystal shape | Rarely shows crystals; rounded nuggets and flakes | Cubes, often striated | Thin plates |
If a find passes all the gold tests, the next step is a jeweler or assayer, and our guide on how to tell if gold is real explains which tests are reliable on worked gold. Native gold from a creek is usually alloyed with some silver, so its value is a little below pure gold spot.
Meteorites versus meteorwrongs
Real meteorites are rare finds, and most suspects turn out to be Earth rocks or slag. Use these tells together, not alone:
- Weight: Meteorites feel heavy for their size. A light, porous rock is not one.
- Magnet: Most meteorites attract a magnet. A few rare types do not, but they are very unlikely finds.
- Crust: A fresh meteorite has a thin, dark fusion crust. Older ones may be rusty brown.
- No bubbles: Meteorites are not bubbly. Holes and vesicles point to slag or volcanic rock.
- No streak: Most meteorites leave no streak or a faint gray one. A red-brown streak means hematite, black means magnetite.
- Inside: A small ground window on a stony meteorite shows bright metal flecks and often small round grains (chondrules).
- No quartz: Meteorites do not contain visible quartz crystals or layers.
A university meteorite lab or a meteorite dealer who works with classification is the right route for a real candidate.
How WorthPic reads rock photos
WorthPic runs on the newest and most capable AI model available, tuned for exactly this kind of identification. From photos of a rock, ideally with a broken face, a ruler and the streak on a tile, it reads color, luster, grain, crystal shape, layers, bubbles, crusts and wood or fossil structure, and suggests what the rock or mineral is and whether it belongs in one of the valuable groups. It flags the common lookalikes, such as slag or magnetite for meteorites and pyrite or mica for gold, and gives an honest value range, which for most rocks is close to nothing. What a photo cannot know is weight, hardness, magnetism or chemistry; your tests fill those gaps, and noting the results helps. It identifies and estimates. It does not authenticate, grade or appraise. For a possible meteorite, gold or a fine mineral specimen, the right people are a university geology department, a meteorite lab, an assayer or a mineral dealer.
Common mistakes
- Assuming that a shiny, heavy or odd-colored rock must be valuable. Most are common.
- Judging by the color of the rock rather than the color of its streak.
- Taking magnetism as proof of a meteorite. Slag and magnetite are far more common.
- Breaking a suspected meteorite in half. Grind a small window instead; labs want it whole.
- Cleaning finds with acid or a wire wheel. It damages crusts, crystals and fossils.
- Collecting in national parks, or taking more than personal-use limits from federal land.
- Pricing from asking listings. Rocks and minerals are listed far above what sells.
What to photograph
- The whole rock in daylight with a ruler or coin for scale.
- A fresh broken or ground face, close and in focus.
- The streak on the back of a white tile, next to the rock.
- The rock on a kitchen scale.
- The rock with a magnet stuck to it, or not.
- Any crystal faces, layers, bubbles, crusts or fossil shapes up close.
- A note of where it was found.
When to get it looked at in person
Common rocks, slag and quartz pebbles need no outside opinion. A local rock and mineral club is the best first stop for anything you cannot name; members are glad to help and see thousands of finds a year. For a possible meteorite, contact a university meteorite lab, many of which publish how to send photos and samples. For possible gold, an assayer or a jeweler who buys scrap can test it. For a fine mineral specimen, a mineral dealer gives an honest buy price. If the find is not a rock at all, start with our guide to identifying a found object.