Petrified wood is a type of fossil that started out as a tree but now more closely resembles a stone. That’s because it that has undergone permineralization, a process that occurs when minerals gradually fill in the tree’s cavities. The value of petrified wood depends on the size, color, and quality of the piece, slab or log. If you’re looking to buy or sell, check with a local appraiser, search eBay, and/or search for online forums with gem or mineral collectors.
How Does Petrified Wood Form?
Normally, when a tree dies, it decays like any other organic material and leaves no permanent record behind. However, if a dead tree is buried in mud or otherwise protected from the normal elements that cause decay, it can be preserved as a type of fossil. In the case of petrified wood, the surrounding groundwater can deposit silica and other minerals that very slowly replace the tree’s organic substance. Gradually, additional minerals and compounds in the groundwater percolate through the tree and add unique color patterns to the wood. The minerals that comprise petrified wood depend on the geographic location of the wood and the conditions under which it is formed. In the western United States, for example, petrified wood is often made of quartz, which is a silica mineral.
Because it is composed of minerals, petrified wood is much heavier than a regular tree log; petrified wood can weigh anywhere between 150 and 200 pounds per cubic foot.
Where Can I Find Petrified Wood?
Petrified wood can be found in locations across the United States, as well as in faraway locations like Madagascar and Myanmar. It can be present on the surface of the ground or buried underneath.
In the United States, the most famous location for petrified wood is the Petrified Forest National Park in Arizona, as it contains one of the largest and most colorful collections of petrified wood in the world. The petrified wood in this park is mostly the result of fossilized conifer trees (i.e. pine trees) that first grew during the Triassic period and have fossilized over the past 220 million years.
Other well-known locations for petrified wood include Ginkgo Petrified Forest State Park in Washington State, which includes 20 varieties of fossilized trees that originated 15 million years ago, and the Mississippi Petrified Forest, which includes fir and maple trees that originated 35 million years ago. Besides these major locations, smaller pockets of petrified wood can be found across the United States. Petrified wood typically begins in areas that are heavily wooded — but because it takes millions of years to form, petrified wood may be found in any present-day climate or ecosystem.
Can I Take Petrified Wood from Public Land?
Some states allow you to take petrified wood from state parks, but before you get too excited about the idea of harvesting petrified wood from a park, you should familiarize yourself with your state and national laws in order to avoid legal trouble.
Some states prohibit individuals from taking petrified wood from public lands, while other states allow it as long as the individual plans to use the petrified wood for personal and non-commercial purposes (which means you can’t sell it). For example, the Arizona Bureau of Land Management’s policy does not allow park visitors to take petrified wood for commercial use, but it does allow individuals to collect up to 250 pounds per year for private use from state parks. Federal law doesn’t allow you to take petrified wood, so if you’re in a national park, don’t even think about it.
For example, visitors are prohibited from removing petrified wood from Arizona’s Petrified Forest National Park, because the national law prohibits visitors from removing “any natural or cultural object from the park, including fossils, rocks, animals, plants, and artifacts.” Anyone who damages or takes petrified wood from the park is subject to a fine of at least $325. Because the laws vary so greatly, the best way to determine the applicable regulations is to contact the park you plan to visit and ask for clarification. But, as a rule, you’ll likely need to buy petrified wood.
How Much Is Petrified Wood Worth?
Petrified wood is known for being aesthetically pleasing, with a soft luster and hues of green, blue, and orange. Because it is so beautiful, petrified wood is considered a semi-precious gemstone. It is often used in lapidary work and turned into items such as jewelry, clock faces, paperweights, and sculptures. In addition, petrified wood can be valuable to paleontologists, as it allows them to study geological conditions from millions of years ago. Because of its beauty and scientific significance, petrified wood can be valuable — but that isn’t necessarily always the case.
There’s no simple price-per-pound formula when it comes to determining the value of petrified wood value. That’s because many factors influence the value of petrified wood. Your best bet is to have a piece of petrified wood professional appraised. You can ask for an assessment from the International Gem Society. Small samples of low-quality petrified wood may not be worth anything, while a high-quality petrified wood log can sell for several hundred dollars. And large items that have been manufactured out of polished petrified wood, such as tabletops, can sell for thousands of dollars.
There are, however, some key factors that influence how much sellers can earn from petrified wood:
- Size: This is perhaps the most important factor in determining the worth of petrified wood. In the majority of cases, the larger the piece of petrified wood, the more valuable it will be. Some samples of petrified wood are the size of small pebbles and are worth only a few pennies, while other samples can be entire petrified wood logs, which are worth much more — into the hundreds or even thousands of dollars, in some cases.
- Quality: Petrified wood is known for being a particularly brittle fossil. It’s natural for it to decrease in quality over time as it is exposed to oxygen and begins to decay. If there are cracks, holes, or any other type of damage, the petrified wood will not be very valuable.
- Color: Depending on what kind of mineral is contained inside the wood, petrified wood comes in a wide variety of colors, including shades of green, blue, orange, red, pink, and brown. Petrified wood that contains bright or unusual colors is more valuable than brown petrified wood. Certain types of petrified wood, like opalized wood, may sell for much higher prices (as these types are very rare). If the petrified wood contains notable characteristics such as growth rings (the rings that accumulate as trees age) or a clearly discernible bark pattern, it is typically more valuable.
- Polish: If the petrified wood has been polished, it is more valuable. The best way to improve the value of a sample of petrified wood is to polish it by using a rock tumbler, a rotary polisher, or another polishing method.
- Geography: If the petrified wood was found in a location where it is typically rare, it may be worth more. In addition, if the petrified wood was discovered in a location that has a sentimental value to the buyer, it may sell for a higher price.
How Does Size Affect the Value of Petrified Wood?
Small pieces of petrified wood are quite common and not worth very much. Tumbled or rough pieces that are one- to three-inches long will typically be worth a dollar or two each, if that. Bulk lots of these pieces are often purchased for even less per individual sample. On the other hand, a petrified wood log weighing 50 pounds could sell for $150 or more. Intact pieces of this size are much rarer than the smaller pebble-like specimens.
The value will continue to increase for larger and heavier specimens. For example, one gem website featured a 189-pound petrified wood log (13 inches by 24 inches) for $625. A petrified wood log that has a very bright or unusual color pattern could be worth even more.
How Does Coloring Affect the Value of Petrified Wood?
Along with size, color is one of the biggest factors in determining the value of a petrified wood sample. Most petrified wood is a muted brown or gray color, so these pieces will typically earn the lowest prices. Other fairly common colors are green, gold (from pyrite), dark red, and orange-red. Colors like blue and violet are much rarer and will sell for more money. As a rule of thumb, the brighter or more intense the coloring, the more the petrified wood will be worth.
Keep in mind that it’s typically not the petrified wood itself that’s worth money, but what it can be made into that makes it valuable. As a result, the key factor in appraising petrified wood is its aesthetic value and potential for decorative use. Rough (unpolished) agatized petrified wood with any of the common color patterns will typically sell for about $2.50 per pound.
How Does Polishing Affect the Value of Petrified Wood?
As mentioned above, polished specimens of petrified wood are typically more valuable than unpolished specimens — so if you want to increase the value of your petrified wood, you likely want to polish it. To polish small pieces of petrified wood, you can use a rock tumbler, which is a small device that does all of the hard work for you. Polishing with a rock tumbler is a simple process which requires adding petrified wood, water, and abrasive grit to the machine and letting it operate for three to four days. For larger pieces of petrified wood that do not fit in a rock tumbler, you might want to try using a rotary polisher, which is a handheld tool that allows you to buff the rock until it is polished.
The effect of polishing on value also depends on the form of the petrified wood.
For example, very small (under 2″) pieces will not be worth more than a few dollars, whether polished or rough. Rough limbs that are a few inches in length are typically worth only $4-$8. Polishing one end of the limb to reveal the color and grain detail can increase the value up to $10-$20. A fully polished 3″ sphere may be worth up to $50-$60 dollars.
Where to Buy or Sell Petrified Wood?
If you have your petrified wood professionally appraised, you may want to ask the appraiser where you can sell it locally. Otherwise, you can use an online auction site like eBay to sell petrified wood. This can be a particularly good option if you’re unsure how much a buyer would be willing to pay for your specimen. Be sure to base your estimates on “sold” items as currently listed items may not reflect actual selling prices.
You can also search online for forums with gem or mineral collectors who may be interested in purchasing petrified wood. You can ask the forum for recommendations of local places to sell or connect with buyers directly. Keep in mind that because petrified wood can be quite heavy, shipping may be prohibitively expensive for large pieces. In such cases, finding a local buyer will probably be your best bet.
Pawn shops near you may also deal in petrified wood.
If you’re looking to buy petrified wood, check the same channels: eBay, online forums, and pawn shops.
Petrified wood itself is not rare, but a large, high-quality piece can sell for hundreds of dollars to the right buyer. The value of petrified wood varies. Gem collectors may be interested in petrified wood, as well as artisans who use the material to create jewelry, clock faces, tables, and other decorative objects. Paleontologists and geologists are also interested in petrified wood.
If you have petrified wood in your possession, you can sell it through a local appraiser, on an online auction site such as eBay, or by connecting with a buyer through an online community.