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So, you’re interested in rockhounding, but what are the signs that rock is valuable? Distinguishing rocks from other building materials such as slag or brick is the first step to making accurate observations when you hunt for rocks. What are the signs that rock is valuable?
The following factors can determine a rock’s value:
- Location
- Color
- Hardness
- Weight
- Streak
- History
Searching for valuable rocks is an engaging hobby that can sometimes yield a little extra cash, and in some instances, you may make an incredibly profitable discovery. Rockhounding, or amateur geology, is quickly becoming popular with people of all ages who want to escape the busy world and explore the outdoors. Unlike most hobbies, rockhounding is inexpensive and only requires a few tools. With a bucket, a hammer, safety goggles, and a magnifying glass, you can begin your search for valuable items.
If you are interested in checking out the best books about rocks and minerals identification you can find them by clicking here (Amazon link).
How Does the Location Affect the Search for Valuable Rocks?
If you want to discover valuable rocks, you can find a lot of helpful information from your state’s geological survey. Without researching your state’s mineral, gem, and precious metal sites, you may have trouble deciding the best location to search.
Knowing what valuable materials are nearby will help you narrow down your search. For instance, if you’re hoping to find opal or quartz rocks, you can search (with the appropriate permission) near areas where the stone is collected for commercial uses.
For a small fee, you can purchase a geological map for your state that displays the best areas to search for rocks and artifacts. The following list displays locations you can visit for your next rockhounding trip.
- Parks
- Rock quarries
- Pay mines
- Creek beds
Parks
Nearly all rockhounding and gold panning are prohibited in the National Parks System. You cannot remove rocks in the National Parks without risking a hefty penalty and criminal charges.
For people that have mineral claims to a section of federal land, the government conducts an environmental study before allowing the removal of any rocks or artifacts.
On rare occasions, private companies with legitimate claims can extract large amounts of material for commercial use.
However, individual rockhounds are limited to two locations in the United States if they want to collect rocks on federal land.
Whiskeytown-Shasta-Trinity National Recreation Area
Whiskeytown, California, is the only area of the National Parks system (in the contiguous United States) that allows gold panning.
There are plenty of private sites that charge a small fee for gold panning, but if you want to find gold at a National Park, Whiskeytown is the place to go.
Gold panning is a popular attraction at the park, but there are restrictions. You’re only allowed to use a pan and trough to search for gold, and you’re prohibited from selling any gold you collect.
Devices such as metal detectors and scuba gear are not allowed for gold panning.
Wrangell St. Elias National Park, Alaska
The largest national park in the United States, Wrangell St. Elias, allows limited collections of rocks and minerals. For rockhounds, the park is an incredible place to explore and collect limited quantities of stones.
Although you can pan for gold and collect specific kinds of rocks and minerals, you’re prohibiting from removing fossils, gemstones, silver, or platinum.
Because of the vast accumulation of glaciers and volcanic sites, Wrangell St. Elias is a geologist’s dream location. If you’re a rockhound planning a trip to Alaska, you’re sure to find some interesting rocks.
Rockhound State Park, New Mexico
The only state park in the country that allows free collecting is Rockhound State Park. Visitors are allowed to carry home a small number of rocks and minerals.
Quartz and agates are abundant in the park, but you’re prohibiting from using digging or prospecting equipment to remove the rocks.
Rock Quarries
Rock quarries are an excellent location for discovering valuable rocks and artifacts. Some quarries allow collections to take place on the actual site, while others reserve an area nearby for the public to collect items.
Whether they are active or abandoned, most quarries reside on private land. Before searching for rocks in a quarry, make sure you have permission from the owners.
Quarries can be dangerous places if the site is active, and you must take precautions when exploring the area.
In addition to your rockhounding tools (Amazon link), you should wear a hard hat and sturdy boots when searching in a quarry.
Falling rocks and sinkholes are potential hazards you should be aware of and never venture into an area designated as off-limits to the public.
Quarries are created to extract building materials for construction projects, and a large number of quarry materials like sand or gravel are not very valuable.
However, some of the material is valuable, but you may spend a while searching before you discover anything.
The following list displays some of the valuable items you may find at a quarry.
- Quartz
- Garnet
- Marble
- Pyrite
- Jasper
- Tourmaline
- Deerite
- Howieite
- Zussmanite
Deerite, howieite, and zussmanite were first discovered in 1965 at the Laytonville Quarry in California. Because of their rarity, the three minerals are highly prized by California rockhounds.
Pay Mines
Several mines across the country are open to the public for gem, rock, and precious metal collection. Of the fifty states in the US, thirty-nine have mines or collection sites that allow rockhounds to collect items.
This article will not include details on every mine in each state but will present examples of the states that may interest rockhounds who are searching for valuable rocks.
Arkansas (link to an ultimate guide about rockhounding in Arkansas)
| Mine | Rock, Mineral, Stone |
|---|---|
| Sweet Surrender Crystals | Quartz |
| Ron Coleman Mining | Quartz |
| Jim Coleman Mining | Quartz, Adularia, Calcite |
| Dixie Crystal Mining Co. | Phantom Quartz and Clear Quartz |
| Crater of Diamonds State Park | Diamonds, quartz, jasper, garnet, barite |
| Board Camp Crystal Mine | Quartz |
California (link to an ultimate guide about rockhounding in California)
| Mine | Rock, Mineral, Stone |
|---|---|
| Roaring Camp Mining Company | Gold |
| Oceanview Mine | Morganite, Kunzites, Tourmaline |
| Modoc National Park | Obsidian |
| Himalaya Mine | Quartz, Topaz, Tourmaline, Lepidolite |
| Gold Prospecting Adventures | Gold |
| Golden Caribou Mining | Gold |
| Benitoite Gem Mine | Benitoite |
Montana (link to an ultimate guide about rockhounding in Montana)
| Mine | Rock, Mineral, Stone |
|---|---|
| Spokane Bar Sapphire Mine | Sapphire |
| Gem Mountain Sapphire Mine | Sapphire |
| Crystal Park | Quartz |
| Blaze-N-Gems | Sapphire, Garnet |
| Baisch’s Dinosaur Digs | Fossils |
One of the most sought-after mineraloids, the opal, is highly abundant in Nevada.
Nevada (link to an ultimate guide about rockhounding in Nevada)
| Mine | Rock, Mineral, Stone |
|---|---|
| Royal Peacock Opal Mine | Opal |
| Rainbow Ridge | Opal |
| Kokopelli Opals | Opal |
| Bonanza Opal Mine | Opal |
If you’re looking for Herkimer diamonds, New York is the place to visit. Herkimer diamonds are quartz crystals (double terminated) that were discovered in outcroppings of dolomite.
New York (link to an ultimate guide about rockhounding in New York)
| Mines | Rock, Mineral, Stone |
|---|---|
| Paradise Falls | Herkimer Diamond |
| Herkimer Diamond Mines | Herkimer Diamond |
| Crystal Grove Diamond Mine | Herkimer Diamond |
| Barton Garnet Mine | Garnet |
| Ace of Diamonds | Herkimer Diamond |
North Carolina, with thirteen public sites, has more open mines than any other state. Although the state is famous for emerald discoveries, you can also find sapphires, rubies, gold, moonstones, aquamarine, and many other minerals and stones in North Carolina.
North Carolina
| Mines | Rock, Mineral, Stone |
|---|---|
| Sheffield Mine | Star Ruby, Sapphire |
| Rose Creek Mine | Ruby, Sapphire, Quartz, Moonstone, Garnet |
| Mason’s Ruby and Sapphire Mine | Ruby, Sapphire |
| Mason Farm Staurolite Prospect | Staurolite, Sapphire, Ruby, Corundum, Gold |
| Lucky Strike Gold and Gem Mine | Gold |
| Little Pine Garnet Mine | Garnet |
| Emerald Village | Emerald |
| Emerald Hollow Mine | 62 various minerals and gems |
| Eureka Gold Panning | Gold and Gems |
| Crabtree Emerald Mine | Emerald |
| Mason Mountain Mine | Ruby, Rhodolite |
| Cherokee Ruby and Sapphire Mine | Ruby, Sapphire |
| Brushy Creek Mine | Garnet, Beryl, Tourmaline, Garnet, Aquamarine |
Before you travel to a mine for rockhounding, contact the mine’s central office to find the admission charge and hours of operations.
Some outfits allow you to dig in the mines with a reservation, and others only allow visitors to sort through prepared piles of gems and stones brought from the mines.
Creek Beds
Creek beds are a common location for rockhounding. One of the most significant advantages of searching in a creek bed is the clean appearance of the rocks. Unlike the stones found in quarries and mines, the Creek rocks appear shiny.
Over time, the rocks in creek beds are polished by the sediment and moving current of the creek. Some of the stones you’ll find look like a rock tumbler has conditioned them.
This makes the identification process much easier because you don’t have to remove dirt or debris to see the stone’s true colors.
In addition to rocks, precious metals, and gemstones, creek beds are also great locations for searching for fossils. If you’re searching for a dry bed, bring some water along to use in your bucket.
Rinsing the stones in water brings out their color and markings. If you’d like to view an exciting video featuring a rockhound searching for valuable rocks in a creek bed, click here.
The following list displays some of the treasures you can find in creek beds.
- Gold
- Corundum
- Tourmaline
- Opal
- Topaz
- Onyx
- Quartz
- Agate
- Pyrite
- Obsidian
- Serpentine
Gold is a welcome discovery at a creek bed, but you’re unlikely to find a mother lode that makes you instantly rich. Commercial outfits have already excavated most of the principal veins of gold and other precious stones.
Large discoveries still occur, but experienced rockhounds broaden their focus during creek bed searches and look for anything unusual that stands out from the rest of the rocks and minerals.
Gemstones like agate are not valuable because they are rare, but unique colors and patterns on an agate can increase its value. Quartz crystals are incredibly common, but unique amethysts can be worth several thousand dollars.
When you search in a creek bed, look for rocks that seem like they don’t belong with the others, and sometimes, you’ll get lucky with a valuable item.
TIP: Gemstones are rare treasures that can be round in natural environments around the world. Find out the best tips on finding gemstones in rivers and creeks in the article below:
8 Tips On Finding Gemstones In Nature (Rivers & Creeks)
What Does the Color Signify When Searching for Valuable Rocks?
The color of rock can help you identify if it’s valuable or not, but it is not a determining factor. Pyrite is famously known as fool’s gold because some early prospectors thought the mineral was gold.
Although pyrite is not as valuable as gold, the mineral sometimes occurs in the same rock formations as gold.
A pyrite discovery may signify that there is nearby gold, and some large pyrite rocks contain gold that can be extracted. So, if you see a rock that has a gold metallic sheen, it’s a good idea to grab it even if it’s pyrite.
Bright, colorful rocks are generally more valuable than dull, dark stones. Gold and emeralds are examples of brightly colored stones that are valuable.
However, an unpolished diamond is not as attractive as the finished product, but it’s highly valuable.
The following list displays brightly colored rocks that are valuable.
- Gold
- Silver
- Ruby
- Emerald
- Sapphire
- Garnet
- Tourmaline
- Opal
- Red Beryl
And here is the table with valuable rocks and their color explanation.
| Rock | Color Explanation |
|---|---|
| Gold | The metal has a metallic yellow color and can sometimes be found near pyrite deposits. |
| Silver | Silver has a shiny white appearance and is often found inside argentite and chlorargyrite minerals. |
| Ruby | The gemstone is a corundum that has a pink or red appearance and is similar to spinel in color and location sites. |
| Emerald | The beryl variety has a green color due to small amounts of chromium. |
| Sapphire | Sapphires are corundum that can be blue, yellow, purple, green, or orange. |
| Garnet | Garnets are silicate minerals that can be almost any color, but blue is the rarest and most valuable. |
| Opal | Opal is a mineraloid that can be white, orange, red, green, black, colorless, blue, pink, yellow, or red. Black opals from Australia are the most valuable. |
| Red Beryl | Red beryl has brilliant red color and is extremely rare. The most substantial quantity of red beryl is found in Western Utah. |
The color of rock can help you decide if it’s worth keeping, but the color alone cannot guarantee the rock will yield a hefty profit.
Red beryl is valued higher than blue beryl because of its rarity, but a sample that has several imperfections will have a much lower monetary value.
In most rocks, you’ll find small intrusions of other elements embedded in the surface. Semi-precious stones like garnets and opals are more valuable when they show fewer intrusions.
An unblemished blue garnet can sell for as much as $7000 a carat, but an imperfect one with intrusions may go for as low as $500 a carat. Pure color is essential when determining value, but so is clarity.
For translucent crystals like quartz, clarity makes an enormous difference. Quartz that has a shiny, clear appearance is far more valuable than ones with a milky or cloudy color.
BTW: Do you want to know more about rock and mineral identification? The books listed below are the best ones you can find on the internet (Amazon links):
- Smithsonian Handbooks: Rocks & Minerals
- Gemstone & Crystal Properties (Quick Study Home)
- Ultimate Explorer Field Guide: Rocks and Minerals (National Geographic Kids)
How Does a Rock’s Hardness Determine if It’s Valuable?
A rock’s hardness is another sign that it can be valuable. Diamonds are harder than any material on Earth, and they can sell for up to $15,000 a carat.
Harder rocks and gemstones are an indication that they may be valuable, but like the rock’s color, hardness is not a determining factor.
Granite is much harder than gold, but it’s far less valuable than gold. Precious metals like gold and silver are softer than most of the items you’ll find rockhounding and their more malleable nature can help you set them apart from similar rocks.
In 1822, Friedrich Mohs developed a scale to measure a rock’s hardness. The Mohs hardness scale assigns a number between one and ten to each stone to represent its hardness. Ten is the hardest (diamond), and one (talc) is the softest.
To get an idea of a rock’s hardness on the Mohs scale, you can examine the following chart.
| Rock, Mineral, Metal | Mohs Value |
|---|---|
| Diamond | 10 |
| Corundum | 9 |
| Topaz | 8 |
| Quartz | 7 |
| Granite | 6.6 |
| Feldspar | 6 |
| Deerite | 6 |
| Apatite | 5 |
| Platinum | 4.5 |
| Fluorite | 4 |
| Calcite | 3 |
| Silver | 2.75 |
| Gold | 2.5 |
| Gypsum | 2 |
| Talc | 1 |
A Mohs scale is a helpful tool for experienced rockhounds, but it’s an ordinal scale that doesn’t represent a rock’s absolute hardness.
Since the scale isn’t proportional, the diamond and the corundum appear to be close in hardness. However, a diamond is four times harder than a corundum.
In a laboratory, a geologist uses a sclerometer to test rocks for absolute hardness. The device measures the width of a diamond’s scratch on the rock to determine the correct value.
Since most of you can’t bring a sclerometer with you on a rockhounding trip, the Mohs scale is a useful alternative to determine a rock’s hardness.
If you bring a penny, steel file, sandpaper, and a small piece of glass with you on your trip, you can test rocks with the Mohs scale to estimate their value.
A rock that you can scratch with your fingernail has a hardness of 2.5. A rock scratched by a penny is under 3, a glass scratch denotes a hardness of 5.5, a steel file scratch is a hardness of 6.5, and sandpaper scratches are a hardness of 9.
You can purchase a Mohs testing kit (Amazon link) that will provide a more accurate representation of the Mohs scale. The kit contains files that are made from apatite (5), orthoclase (6), quartz (7), topaz (8), and corundum (9).
The kit does not contain a diamond (10) file, but the only material that can scratch a diamond is another diamond.
TIP: The mineral’s hardness is one of the most helpful characteristics in mineral identification. Check out the ultimate guide on testing mineral’s hardness in the article below:
DIY Guide: Testing Mineral’s Hardness (Explained by Expert)
How Does a Rock’s Weight Help Determine its Value?
Another way to determine a rock’s value is by measuring its weight. You don’t have to bring a triple-beam scale with you, but you can observe how heavy the object is when you pick it up.
Generally, precious metals have a greater mass than less expensive rocks.
The weight alone will not define a rock’s value, but it can help you when comparing it to other samples. For instance, a large chunk (the size of a baseball) of pyrite will not feel as heavy as a large piece of gold. Pyrite is a brittle substance with a much lower density than softer gold.
Although they rate low on the Mohs scale, precious metals like gold, silver, and platinum have higher densities and are extremely valuable.
You can’t apply the same reasoning to a material like lead since it has a high density, low Mohs value, and is not as valuable as precious metals.
However, even amateur geologists should be able to discern the difference between lead and precious metal.
Lead isn’t a rock, but it’s sometimes found among other items in dry creek beds.
How Can a Streak Test Display a Rock’s Value?
Another method you can use to identify a rock’s value is a streak test. A piece of white porcelain or ceramic is the ideal tool to use to discover which minerals are contained in the rock.
To perform the test, scrape the rock against the porcelain and observe the color streak. You can match the color of the streak with the mineral colors on an identification chart. Some stones have streaks that differ from their exterior color like pyrite.
Although pyrite is a dull gold color, its color streak is black. When you scrape a piece of pure gold against porcelain, it produces a gold stripe. This test is an excellent way to discern the difference between pyrite and pure gold.
Apatite is a mineral whose surface color can be dark green or red, but it produces a white streak when you test it. The test is only valid when you test rocks that are softer than porcelain. Porcelain has a hardness of 7, and anything that has a hardness above 7 will not produce a streak.
Rocks are often composed of more than two minerals, and the surface color can hide what’s beneath the surface.
Having a chart with photos of stones in their unpolished state will help you identify the rocks quicker, and the streak test will confirm each mineral’s composition.
Although it may seem to limit, the streak test will work on most of the rocks you’ll find. Most rocks fall under 7 for hardness, and the harder ones are much easier to identify than the softer rocks and minerals.
The rocks above 7 include topaz, corundum, and diamond.
How Does a Rock’s History Affect Its Value?
Although a rock’s appearance, abundance, and size are factors that determine its value, the historical significance of the stone can also affect its price. When you’re searching in a creek bed or quarry, you probably won’t find rocks with an interesting backstory.
Rocks that are valuable because of their history are more likely to show up at an auction, pawn shop, jewelry store, or yard sale. A quartz crystal discovered 120 years ago will be worth much more than one that was found last year.
The age of the rock’s discovery and the reputation of the original owner can increase the price of an inexpensive stone. A piece of polished obsidian owned by George S. Patton would cost far more than a similar rock you found last weekend at the quarry.
If you shop at yard sales or flea markets, be on the lookout for cheap rocks. Rocks are not a common yard sale item, but people occasionally sell rocks along with their inexpensive jewelry. You might get lucky and find a granite paperweight owned by Elvis.
TIP: There are three main types of rocks (igneous, metamorphic, and sedimentary), and the time for their formation differs dramatically from a few days to millions of years. Find out more in the article below:
How Long Do Rocks Form? Answers For ALL Types of Rocks
How Do You Search for Valuable Rocks on Private Land?
Before you go rock hunting, verify that the area you search does not require a permit or official authorization. Some parks allow limiting rockhounding, but most need you only to remove rocks that are in plain sight.
Archeological sites and historical landmarks are off-limits to rock hunters, and some areas impose stiff fines and possible prison time for violators.
Have fun on your rockhounding adventure, but remember to follow the guidelines and restrictions in the area you search for.
For public land searches, you can contact your states’ Bureau of Land Management (BLM) for permission to rockhound. If you want to search on private land, you’ll have to talk to the owners to get approval.
Private owners run most quarries and private mines. Although they are plenty of locations around the country to hunt for rocks, more private owners are becoming hesitant with welcoming rockhounds.
Individuals who don’t follow the rockhound’s code of conduct have tarnished the reputation of amateur geologists. Some careless hunters have disturbed the work site by littering, interfering with extraction equipment, and digging in unapproved areas.
Always respect the area you search and thank the owners with an email or letter to show your appreciation. It’s a daunting task for an individual rockhounding to seek permission on a private site. If the owners are wary of trusting an unknown rockhound, they may refuse to allow your search.
One way to gain the trust of local owners is to join a respected rockhounding group that has a clean record of searching on private lands. Groups usually have better luck with private owners than individuals.
A Note About Meteorites
The jackpot for every amateur rockhound is a meteorite discovery. The stones resemble volcanic rock that has been covered with melted slag. The stones will have a burned appearance and will not look like the native rocks.
Since they’re not native to this planet, meteorites are much rarer and expensive than all of the precious metals and gemstones. A pound of meteorite material can be worth 1 million dollars.
Some rock hunters only focus on searching for meteorites, and they hold on to the hope that they’ll receive a big payday with a massive discovery.
Like winning the lottery, meteorite discoveries are a dream shared by many people. However, you’re more likely to win a jackpot a couple of times than discover a piece of space rock.
Meteor events are incredibly unlikely, and it’s even more unlikely that a meteorite will land in an area where you can claim it as your own. It’s ok to hope for a meteorite discovery, but don’t waste your time searching for the rarest rock in the universe.
Some people sell pieces of meteorites online and offer low prices that don’t seem possible. Never purchase an expensive rock without examining it first.
Online shopping is safer and more reliable than ever, but there are still con artists that sell fake meteorites for discounted prices.
Pieces of basalt have been modified to appear as space rocks, and several thoughtless people have made thousands of dollars off a twenty-dollar volcanic rock.
Closing Remarks
Searching for attractive and valuable rocks is an engaging hobby that allows you to enjoy the natural surroundings. At the same time, you learn about the geological history of a creek bed or quarry.
When you search in locations abundant with valuable rocks and minerals and observe the color, hardness, streaking, and historical significance of the rocks, you’ll increase your odds of making a profitable discovery.
So, grab your hammer, bucket, and safety goggles, and unearth that elusive musgravite stone.
TIP: If you are looking for some tips on the best rockhounding equipment, check out my list of recommended hammers, chisels, picks, and bars for rockhounding:
Recommended Rock Hammers, Picks, Chisels & Bars For Rockhounding