I once had a person ask me about sharpening stones as in “how to sharpen knives, etc.” What sort of stone is best—natural or synthetic? This thought of sharpening stones brought back a flood of memories---mostly of sweaty work on a hot and humid Kansas summer day.
Growing up in a rural area my summers seemed to be spent playing sandlot baseball, fishing, and working—in no particular order. Remember, my childhood was spent in pre-federal work rule days so you could “legally” work at any age with or without “dangerous” tools. Two of these tools I dreaded were the machete and the scythe, for these meant some really sweaty times "were a comin"; both tools were common on farms and in town homes. Usually, sometime in July, a local farmer would show up in my father’s place of business and ask “if Mike wanted to work today (and tomorrow)”. Of course my father always replied in the affirmative without asking about my fishing plans. At any rate, some of my earlier jobs entailed walking through corn fields with a machete hacking down thistles and Johnsongrass. Boy, was that a hot and sweaty job with the only water being a stone jug with a wet “gunny sack” wrapped around it. Oh well, it represented money to buy new baseballs but especially baseballs cards looking for that elusive Mickey Mantle. Come August and the wild sunflowers, with wild bees and flying ants (we called them pissants), were getting larger around the edges of the fields so out came the scythe—an instrument of torture for a young kid. But, again ---money for a new fishing pole.
A scythe, and sickle, with the sharp part of the blade on the inside. Many scythes, as least from my foggy childhood memory, had a small perpendicular handle (for the left hand) on the main handle. Sketch courtesy of Wikipedia.
Well, what I learned early on was that it was imperative to keep both tools sharp at all times in order to make life a little easier. Most everyone had two instruments for this task, a pedal-powered (or treadle-powered) grindstone and a whetstone. Before heading to the fields in the morning the pedal-powered grindstone was used to remove all nicks from the blade and smooth out the sharp edge while the whetstone was finishing tool. The grindstone has been around for centuries and was used at a slow speed as to not destroy the temper of the blade, as would a power grindstone. Today most people sharpen their lawn mower blade, for instance, with a power rotary grinding tool. In doing so the blade gets very hot, turns rather blue, and the temper is lost. So, the blade will not hold an edge and sharpening at more frequent intervals becomes necessary. Pedal-powered grindstones turn slowly and do not heat up the blade. I also carried the whetstone with me as a portable tool to “keep the edge on” during working hours (and as an excuse to rest).
Being somewhat inquisitive I asked some of the local “old timers” about the stones and learned that the best grindstones were from Ohio and were known as Berea stones while the best whetstones came from Arkansas. Only a few of the “townies” would use artificial carbides as sharpening stones. Later in life as a student I decided to find out more about the collecting localities of these stones.
The Berea Sandstone (Berea Grit of older literature) is of earliest Mississippian age (~345 Ma) with a type locality near Berea, Ohio, just south of Lake Erie and today in the southeast suburbs of Cleveland. The rock evidently was used and quarried by the early 1800’s. The sand grains of the unit are angular, rather than rounded, are rather uniform in size and mineral composition (about 95% silica) and the sandstone itself is, in many beds, free from cracks, pebbles and other impurities; therefore, the stone is an ideal abrasive (Ohio History Central, 2010). The sandstone also was quarried extensively for use in building stone, sidewalks and bridges.
The Berea Sandstone has a very interesting, and complicated, geological history related to a rising chain of ancient mountains in what is now the eastern part of the United States. Starting in the Late Devonian (~360 Ma), but continuing into the Mississippian, parts of the ancient North American continent collided with terrane that is now part of western Europe (geologists call this event the Acadian Orogeny) and large amounts of sediments were shed to the west—such as the “Catskill Delta”. Close to the source area, as in the Catskill Mountains of New York, the resulting rocks are coarse-grained and the grains rather unsorted. Many hundreds of miles away, in a band from Pennsylvania to Ohio to Kentucky, the sediments were deposited by streams flowing into shallow seas. The resulting rocks are fine grained and well sorted and are named the Berea Sandstone. Ohio has produced about 90% of the natural grindstones in the U. S. and many/most were from the Berea Sandstone (Crowell, 1996).
Paleogeographic map of the Early Mississippian (~345 Ma) showing location of mountain building events in the eastern U. S. and the locations of Colorado and Ohio. Modified map courtesy of Ronald Blakey of Northern Arizona University.
The finishing tools for blade sharpening then, and now, included whetstones and the finest, by most accounts, come from Arkansas. Arkansas Whetstones are composed of a material called novaculite, and more specifically quarried from a geological formation formally named the Arkansas Novaculite (Devonian to Early Mississippian in age, ~400 -~345 Ma) found in the Ouachita Mountains. Novaculite is a recrystallized (probably from low grade metamorphism) form of chert or flint (a microcrystalline quartz), and is extremely pure (~99% silica). It has been used by early Native Americans for projectile points and cutting tools and by more recent Americans as sharpening instruments for everything from axes to surgical instruments. In addition, novaculite is quarried for use as road aggregate, riprap, and in the manufacture of items calling for the use of material rich in silica.
As with the Berea Sandstone (of similar geological age), the geological conditions surrounding deposition of the Arkansas Novaculite is quite complex and fascinating. The novaculite was deposited in a marine basin called the Ouachita Trough (actually it extended from Arkansas to west Texas) and according to the U. S. Geological Survey (Cecil, 2004) was “sediment starved “ due to aridity in the area and a restriction of sediments entering from streams. A long time ago, during a field trip to the Ouachitas, we were informed that the source of silica (and there is a tremendous amount) for the novaculite was dissolution of tiny one-celled organisms with a siliceous shell called radiolarians. Other professors argued for the silica coming from submarine volcanic vents, dissolution of volcanic ash, or even post-burial introduction by fluids. Today, geologists with the USGS still are uncertain but a new theory is now on the books—the introduction, and dissolution, of wind- blown silica dust (Cecil, 2004). Whatever the case, the novaculite represents a large source of silica, which later in its geological life, would produce the finest sharpening stones in the world.
Just to top off this discussion of paleogeography, I will remind readers that warm and tropical marine waters invaded the future Colorado during the Devonian and Mississippian periods and large expanses of carbonate muds were deposited. Today these rocks are known as the Chaffee Group, the Ouray Limestone and the Leadville Limestone (of mining fame). So, while the eastern U. S. was undergoing mountain building, the stable interior of the continent was covered by shallow seas, and a deep water trough occupied south central U. S.
As for the question about natural or artificial stones, I suppose that is a personal choice. Today’s artificial stones are complex and come in a bewildering variety of compositions and types; many are instrument-specific. Silica carbide stones may be much less expensive than novaculite whetstones but there is some satisfaction in owning a nice natural whetstone carefully cared for and carried in a leather case.
All of this talk about grindstones and whetstones has opened up a world of new questions---at least for me! At this time I am unable to answer most of them and perhaps some reader could enlighten me. The references (Crowell, 1996) pointed out that 90% of the natural grindstones came from Ohio. How were they shipped to frontier western settlements, especially those without a railroad or ship dock? Were grindstones of local origin in common usage? For example, did sandstones of Colorado produce material for grindstones? I suppose local farmers and ranchers threw down a large piece of hard sandstone in the yard for sharpening purposes but were round wheels constructed? But, I also know that frontier settlements usually had a blacksmith who commonly sharpened tools and itinerant “tinkers” traveled the country sharpening tools and scissors. It is my understanding, but I can’t lay a finger on a reference, that novaculite whetstones were precious possessions and handed down from generation to generation? They certainly would be easier to pack around. But again, did Coloradans use local chert/flint as a whetstone?
These questions then lead to something much larger---millstones, which are actually very large and thick grindstones. Virtually every frontier settlement near a running water source (sometimes wind) had a mill to grind grain. These mill stones, composed of either limestone or sandstone but sometimes granite, weighed many hundreds of pounds (a millstone around my neck=a heavy burden) and again their slow action did not heat up the grain during grinding. So my question—what is the source of millstones used in Colorado mills—local or shipped in? I will continue looking for an answer.
Today, most sharpening is completed using power tools, except for perhaps knives. In fact, it seems as though the sale of Arkansas Whetstones is increasing on a yearly basis. Old-time grist mills using stone millstones and water power (or even electricity) are a source of amazement for me and I have visited several. Most modern mills are steel ball mills, blade mills, or roller mills, except for Hodgson Mills (with North Carolina red granite millstones), the maker of some of my personal grain products.
Cecil, C. B., 2004, Eolian Dust and the Origin of Sedimentary Chert: U. S. Geological Survey Open-File Report 2004-1098.
Crowell, D. L., 1996, From Pulpstones to Bats: Ohio Geology (Ohio Geological Survey).