Fake Arrowheads and Stone Artifacts : Detection And Authentication With A Microscope

The amount of modern made artifacts (arrowheads, spear points, stone tools) today being passed as “authentic prehistoric” is staggering. Some experts estimate that as much as 90% of the arrowheads and projectile points on “e…” (the common internet auction site) are fake.

In any case, each day, arrow heads and stone points are being knapped and made to look authentic by artificial aging. Many of these eventually are put on the market later as being “ancient”. A modern day skilled arrowhead knapper, coupled with the knowledge of artificial aging, can make extremely convincing looking stone artifacts. In these instances, the trained naked eye is not enough to determine authenticity. So where is a collector of prehistoric Native American Indian stone artifacts to go for help? One choice is to get a Certificate of Authenticity (C.O.A.) from a reputable authenticator. Another option is to purchase a good microscope for looking at the arrowheads and stone artifacts yourself. This scientific approach of microscopically examining the patina, surface features, flaking, hinge fractures, age spots, wear, staining, mineralization, etc, will give you important information about the authenticity of your artifact. You will need to know what type of microscopy equipment to purchase as well as guidelines for what to microscopically examine. In this article, we give the information needed to empower the amateur or professional Indian artifact collector to make wiser choices when spending their money. You will be better prepared to separate modern made stone reproduction artifacts from valuable authentic ancient pieces formed by prehistoric hands.

What type of microscope is used for authenticating ancient Indian arrowheads, stone spear points, knives, axes, and other stone tools?

The best arrowhead authenticating microscope would be the low power stereoscopic microscope. We suggest one with a zoom magnification able to go up to 45x with the standard 10x Wide Field eyepieces. You will be able to magnify features of the surface far beyond what the naked eye can visualize. The best examination can only come from using true stereoscopic optics which gives a 3D effect. The stereo microscope uses two different lenses, each with their own independent paths to the surface of the arrowhead. By contrast, a compound microscope uses only one lens, splitting the image in the head to go to both eyepieces. You will need the stereoscopic imaging to be able to see the identifying features on the stone. What price does a good microscope cost? A name brand microscope made in Japan may be $2000 and way over your budget. A comparable piece of equipment with excellent capability may be found at stereomicroscopes.com for much less cost. While you can get something really cheap and basic, remember that the cost of expensive equipment would be recuperated upon detection of a single high value fake reproduction point you were about to purchase as authentic.

Recommended stereo zoom microscope with trinocular port for photography: http://stereomicroscopes.com/003t000m.html

Recommended stereo zoom microscope w/o photography port: http://stereomicroscopes.com/003b000m.html

What specific details are examined by the professional stone artifact authentication expert when checking for fake arrowheads and projectile points in a collection?

Mineralization:
Over the ages, an authentic artifact often acquires mineral deposits and growths on its surface. One is iron ore, and can be seen under the stereo microscope. A faked arrowhead may have been artificially mineralized by rubbing a rusty nail over the high ridges. The mineralization will not be deep into the specimen, and especially not in the deep fractures or cracks. The stereoscopic microscope can detect if there is something deep inside the cracks. The fake mineralization will appear to be just a thin layer on the surface. Authentic ancient stone arrowheads, projectile points, and knives have the iron deposits looking like it is melted into the stone in a natural way. You can see the smooth texture where the iron ore has naturally affixed itself to the stone rather than being rubbed onto it. Sometimes a “halo” can be seen with the stereo microscope where the natural occurring iron ore deposit meets the rest of the stone. This effect is from the iron ore breaking down as well as the stone absorbing (or bleaching) the deposit. A faked arrowhead or point would not have the natural “halo”.

Organic Deposits:
Many authentic prehistoric arrowheads and artifacts will have spots on them, looking like some tar has been stuck to the stone. This effect is due to decomposition of organic materials over the ages. Authentic stones found in fields, creeks, and the sand can all have this organic deposit on them. Those who artificially age arrowheads may make up a mixture of petroleum based tar products and apply it over the surface of the stone. They may then roll the stone or bury it in the sand or dirt so it appears to have the natural organic deposit. To test if it is natural, get a bottle of acetone (such as in fingernail polish remover), dip a cotton ball with it, and rub the stone, cleaning it well. If the spots come off, then it is probably faked. Another way to check for fake organic deposits is to use a black light and check for tell tale fluorescence of glue or other chemicals that the counterfeiter may have used to create the artificial age spots. You may try the black light with the use of the microscope, and look around the cracks and fractures for any fluorescing.

Hinge and Step Fractures:
When making arrowheads and spear points, there are flakes that are not completely removed from the body of the stone. They leave what is called hinge or step fractures. After eons in the elements, an authentic artifact will usually have this fall off naturally due to repeated freezing and thawing. Evidence of natural aging can also be found at these fractures. Think of this as like a thumbnail and dirt under the thumbnail. As the freezing and thawing occurs, the ends of these flakes (or hinges) rise and fall back, allowing minerals (like clay) to get under the cracks and sometimes makes it look blue color. The cracks as well as the hinge fractures should not look clean (modern) and should have evidence of dirt and debris underneath them accumulated over the years of being exposed to dirt and the elements. Step fractures (like stair steps) are several hinges in a stair-step pattern. This was caused by trying to flake off the piece. Several tries to rid the arrowhead artifact of the flake will cause this pattern. The naked eye will see these steps to be sharp looking, but an arrowhead authenticating microscope will show wear on them. An authentic stone has the pattern looking rounded rather than sharp and uneven as found in fake reproductions. Some counterfeiters use furniture polish to help cover up the hinges as well as make the stone look aged. If the stone fluoresces under a black light, it may be from the use of this chemical having been applied to the surface. Some counterfeit stones have been meticulously “aged” using rock tumblers or even using liquid nitrogen to freeze/thaw and break the hinges.

Surface Wear:
Examine the wear on the surface of the arrowhead or projectile point/knife in question. The face of the stone should show natural wear and be more polished smooth if authentic. The center of the face may be the most polished and would not be as likely to have been touched by any ancient resharpening of the stone. Look closely under the stereo zoom microscope at the ridges. Zoom the magnification in and out and slowly look at the features. An ancient stone would have ridges that are more rounded due to the natural polishing. If the counterfeiter put the stone into a tumbler or put on a grinder to make it look polished, the stone should show striation (scratch) marks as well as the artificial wear would appear more uniform over the whole stone. An authentic point should have more wear in certain locations. The cutting edge is another place to look at for natural wear. If the stone were really used, it would generally have become somewhat dull. Under the microscope using lower power, faked artifacts may look sharp, not like authentic that is usually well rounded and smooth to the eye and touch. The wear at the base of the arrowhead should also be examined. Several types of points such as the Clovis, Dovetail, and Hardin use basal grinding and or lateral edge grinding. This wear will appear to be rounded if authentic. Faked arrowheads and artifacts will have the wear to appear flat and opposing. Looking under the microscope closely will show a fake to have flap marks from the sand paper or grinding wheel as well as the micro-scratches from the sandpaper or steel tools.

Soil Staining:
Authentic natural staining from soil happens after eons of being buried in the ground or one side facing the ground. Set the arrowhead authenticating stereo microscope to 20x magnification and look at the surface of the staining. You should notice some color hazing, looking like a layer of skin that changes the surface color of the artifact. Knappers of fakes often will bake or soak the stones in chemicals to look like natural soil staining. Some apply syrup or some oil, and then bake the faked arrowhead or spear point to give it a stain. Sometimes the fake projectile point is soaked in a solution of cow’s manure. And as mentioned earlier, furniture polish is often used to give an aged look with staining. It is hard for the modern flint knapper to make the staining look evenly coated, so check for that. Also look at the hinge or step fractures under the microscope and see if the stain is darker near them, as might be in a modern point. And as mentioned before, try the acetone on the point to see if it easily removes and also check under the black light for the tell tale fluorescing of applied chemicals. It should also be noted that different stone types do not stain well naturally, such as Flint Ridge flint, some Agates, and Chalcedony. So authentic points made from them may show little or no evidence of soil staining.

Patina on Up or Downside:
If the arrowhead, tool artifact or spear point has been exposed to the surface for years, it will have a heavier patina and weathering pattern on the side facing up that is exposed. Modern flint knappers making fakes generally would attempt to make the faked patina uniform and the same on both sides.

Metal traces and Crushed Flint:
If the fake arrowhead projectile points were made with metal tools, then it may be possible to observe traces of the metal residue on the stone under the stereo microscope using high power magnification of around 45x or higher. Often, when looking at a fake stone artifact under a microscope, one can see tiny copper or steel dots that are residual from the tips of metal tools to remove flakes. Look closely for traces of crushed flint that may be present in a faked point or arrowhead near the notches (hard area to clean). Hold the arrowhead in your hands and move it slowly to examine this area in detail using the stereo microscope. Zoom in as needed to identify what you are seeing, then zoom out to continue searching. If you keep the microscope zoomed in too much, you will have a hard time finding your location on the stone. The crushed flint may appear as a white power and is a sign of being recently made. A fake (reproduction) arrowhead may also have tiny flakes still barely adhering to the surface, while an authentic prehistoric stone would have this worn off over time.

Comparison of Authentic to Fake:
The best way to get a feel for what is an authentic ancient stone tool or projectile point and what is a modern reproduction is to look at both types under the stereoscopic microscope. Take some arrowheads you have found yourself so you know they are authentic prehistoric, and then buy some modern ones that are clearly being sold as reproductions. For all but those with the most advanced faking techniques, you will be able to easily spot the modern fakes with some practice.



By: ZLG; Oct 24, 2009, Revised Dec 22, 2009.