Articles

STONES USED BY PIEDMONT INDIANS

I wrote and had published in the PIEDMONT, which is the publication of the Piedmont Archaeological Society of the Carolinas and Virginia, a series of articles called MINERAL MATTERS.  These articles were about the various stone materials used by the prehistoric natives in this region.  This article will cover some of the MINERAL MATTERS subjects - the rocks used by the natives to chip or flake various projectile points, knives and blades.  And to begin, flint is not a material naturally found in the Piedmont or even in most of North America, so spear points/arrowheads made of flint are not normally found here.  Most of the chipped artifacts found in this area will be made of ryholite, silicified slate, quartz, quartzite and to a lesser extent jasper and chalcedony.  These stones are technically minerals and are found throughout the Piedmont thus were available to the prehistoric Indians. There are a few other minerals used by the natives such as novaculite, argillite, basalt and chert but the six listed above will cover 99 per cent of the chipped artifacts made in the Piedmont.  Since metal ores are not natural to this region, the natives did not develop a means to smelt and thus produce metal tools.  They had to rely on mineral stones to make their implements.

 

Rhyolite

The Piedmont sits on the Slate Belt which was formed by volcanic action 550-650 million years ago.  One of the most common mineral rocks found in the Slate Belt is a lithic material that American Indians, from the Paleo Period (10,000 BC) through the Historic Period (ending around AD 1700), used for tools – rhyolite.

Rhyolite (pronounced RYE-oh-light) is an extrusive igneous rock that was formed by rapidly cooling volcanic lava on the earth’s surface.  It was created by violent volcanic eruptions which hurled hot magma and volcanic fragments high into the atmosphere.  Gravity eventually brought these pyroclasts back to earth where they were deposited as layers which developed into rhyolite.  The Uwharrie Mountains, in the middle of the Piedmont, were volcanoes many millions of years ago when these eruptions were common.  That is why rhyolite is so prevalent in central North Carolina, South Carolina and Virginia today.  These volcanoes could evidently blow their tops for hundreds of miles.

This stone is composed of the same minerals as granite, that being quartz, feldspar, biotite mica and natural volcanic glass.  Unlike granite, which is intrusive meaning it cooled beneath the earth crust and formed coarse grained rock, rhyolite is normally aphanitic or fine grained and, as mentioned before, formed on or very near the earth surface.  The quartz and feldspar crystals in rhyolite normally cannot be seen with the naked eye except in porphyry rhyolite which has relatively large phenocrysts.

Rhyolite, which is found throughout the world, can be black, brown, tan, white, grey, red or green in color.  In the Piedmont, it would have been mostly dark grey or black shortly after the volcanic eruptions but today it has weathered to medium grey and occasionally dark tan, but some will still be black.  Phorphritic  rhyolite is usually black or grey and the crystals show up as tan, white or grey.  Flow banded rhyolite, which was formed as distinct layers of the volcanic material, arrived on the earth surface with such frequency, that the individual layers did not have chances to completely harden before other eruptions rained down from the sky.  It clearly shows swirling layers or bands of differing colors and textures.

Ancient man used this stone for tools because it was plentiful and could be flaked with sharp conchoidal (shell-like) fractures.  The surface luster of rhyolite Indian artifacts will normally be dull but can be slightly waxy and the stone is always opaque.  This is certainly not the prettiest rock in our country but since it was widely distributed, prehistoric man obviously made extensive use of it.  Today, by most estimates, this is the material that was used by the region ancients for perhaps as much as 75 per cent of their tools.  This common material that the casual collector will call flint is in reality the prehistoric Piedmont man’s best friend – rhyolite.

 

Silicified Slate

As mentioned in the section on rhyolite, the Piedmont sits on the Slate Belt.  Because of that name, one might assume that the ancient had access to the mineral slate for their tools.  They certainly did but slate is a low grade metamorphic rock that is too soft for most cutting tools.  Slate itself was formed when shale, which consists of clay minerals, was put under intense pressure with temperatures in the several hundred degrees range.  But here we will discuss silicified slate, which means that the mineral was hardened, again under extreme pressure and heat, into a relatively hard stone that could be used for cutting tools.  Like rhyolite, silicified slate fractures conchoidally and means a piece of the material could be chipped with a very sharp cutting edge.  When geologically formed silicified slate would have been dark grey to black but almost all prehistoric Indian artifacts made of this material will be dark to light tan.  This simply means that the surface of the tools are not as hard as ones being made of rhyolite and thusly weathers (or as we collector say – patinates) more deeply and has more of a color change.  Possibly ten per cent of the prehistoric artifacts found, in the Piedmont, are made of silicified slate except the ones made by the Pee Dee Culture people (AD 1400-1600) whose arrowheads will still be black/grey because they have not had time to patinate to tan. Probably at least fifty per cent of their artifacts were made of this mineral – silicified slate.

 

Quartz

To the east and west of the Piedmont, the lithic material of choice for the ancients was the second most common mineral on earth – quartz.  But that does not mean that this mineral was not used by the natives in this region, since many prehistoric tools have been found, in the region, that were made of this stone.

The mineral quartz is an essential component of igneous rocks such as granite, metamorphic rocks such as gneiss and quartzite and sedimentary rocks such as sandstone.  It is a silicate formed of oxygen and silicone and is crystalline or cryptocrystalline in form.  The cryptocrystalline variety is made up of two sub types – fibrous and granular.  Fibrous quartz used by ancient man includes agate and chalcedony while granular variations are jasper and chert.  But the quartz category most encountered by Indian artifact collectors, in the Carolinas and Virginia, is the crystalline class, so named because this mineral grows into crystals.  In its pure form, it is colorless and is known as rock crystal quartz but pure forms of this mineral are very rare in this region.  Artifacts made of rock crystal quartz are so highly prized that a small industry has developed that produces fake ancient projectile points made of glass or crystal quartz from Brazil.  The most common quartz color that we find is white, which is tinted by the presence of numerous minute liquid and gaseous inclusions.  Among the others are smoky quartz (grey to brown to almost black and often semi-translucent), citrine quartz (tan to yellow to orange) amethyst (purple), aventurine (green) and rose quartz (pink to reddish pink).  Rose quartz, unlike the others, rarely forms into crystals.  All these colors of quartz are found in this three state region and all were used to make flaked tools by the Indians.  White quartz is common throughout all three states (except for the extreme eastern coastal plain) but the other colors are normally found only in the foothills and mountains.

Crystalline quartz can be transparent, translucent or opaque with a luster that is vitreous (glassy), greasy or splendent (shining glossily).  It is a very hard mineral being a 7 on the OHM mineral hardness scale.  The OHM scale is numbered 1-10 with the diamond at a 10 and being the hardest mineral on earth.  Because of the hardness and the fact that quartz will chip with conchoidal flakes, it made sharp tools that could be used extensively without constantly needing sharpening.  Probably ten to fifteen per cent of the prehistoric Indian artifacts found in this region are of this mineral – this very hard and very plentiful stone called quartz.

 

Quartzite

Quartzite is a hard and fine-grained rock that was formed from quartz rich sandstone by precipitation of silica from interstitial water at shallow depth and low pressure – called orthoquartzite, or from high pressure and high temperatures – called metaquartzite.  The average collector will certainly not be able to distinguish between these two, so we normally just call them all quartzite.  The color of quartzite varies but is usually pale grey to tan to brown and is found throughout the Carolinas and Virginia.  It is reasonably plentiful but for some reason only certain ancient cultures seemed to favor this mineral.  The Savannah River time period people (3,000-500 BC) used quartzite for perhaps half their spear points/knives but most of the other prehistoric natives sparingly used this material.  The Woodland and Mississippian Period natives (AD 1000-1700) did seem to favor it for bannerstones and discoidals but not for cutting tools and other than these groups, everyone seemed only to occasionally use this fairly common rock – quartzite.

 

Jasper

Jasper is one of the less common lithic materials used by prehistoric man in the Piedmont.  It is a cryptocrystalline variety of quartz.  To be exact, it is a granular cryptocrystalline variety of chert which itself a variety of quartz.  Jasper artifacts found in this region are red, tan, brown or yellow, the individual colors of which are determined by the amount of finely disseminated hematite or goethite in the stone.  It is opaque to slightly translucent with a dull vitreous to greasy luster.  Jasper flakes with conchoidal fractures and was used to make all types of chipped artifacts from the Paleo to the Historic Periods, though these artifacts are rarely found in comparison to items made of rhyolite, silicified slate or quartz.  Most jasper artifacts found in the Carolinas and Virginia, seem to come from the eastern mountains and the central NC-VA border area, though they can be found from the seashore to the mountains.  For some strange reason one of the hot spots for finding jasper chipped artifacts seems to be Stokes and Rockingham Counties in NC and Pittsylvania and Halifax Counties in VA, all of which border the Dan River.  There must have been one or more outcroppings of jasper in that area.  If you find a brown to red to yellow spear point in the Piedmont, there is a better than average chance that it is jasper.

 

Chalcedony

Chalcedony (pronounced CAL-sid-ah-knee) is a micro to cryptocrystalline variety of quartz whose individual phenocrysts cannot be seen by the naked eye.  It has a distinctive microscopic crystals arranged in slender fibers in parallel bands.  It is found worldwide in many colors such as red, green, black and white and is translucent to opaque and has a waxy or dull luster.  Most chalcedony artifacts found in the Piedmont are tan to white to pale grey and are semi-translucent to translucent.  Raw chalcedony is rarely found in the Piedmont but when it does happen, it is usually as geodes; as nodular or massive forms; stalactitic shapes or as botryoidal figurations.

Chalcedony was used for chipped artifacts from the Paleo to the Historic Periods, but seems to have been used in the Early Archaic Period (9,000-6,000 BC) more than the other times.  Most prehistoric chipped Chalcedony artifacts seen by this writer would fall into this time and are called Palmer Corner Notch and Kirk points.  Chalcedony artifacts can be confused with translucent white quartz and at times a person simply cannot distinguish between the two materials.  But even though prehistoric artifacts were rarely made of this material, it is prized by collectors and a good note is that it is rarely faked.

So keep your eyes to the ground with the hope that you will find a nice Kirk point made of this beautiful quartz family stone – chalcedony.