Neolithic Knife Sharpening Stone?

On a recent trip to Italy, I was hiking around the  Geoparco Del Beigua in Liguria. It contains what is identified as a Neolithic stone for resharpening greenstone axes, among other carved stones. Actually, the entire site consists of reproduction stones, the originals removed for protection. In case you have forgotten (as I did), the Neolithic period is the end of the stone age, generally defined between 4,500- 2,000 BCE. This is right before the copper or bronze age begins.

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Explanatory text at the entrance to the site. Geoparco Del Beigua, Liguria, Italy, 2016.

Stones like this are not unique to Italy, they are found all over Europe, and are simply called “grooves” or polissoirs by archeologists. These stones were first identified as sharpening stones in the mid-19th century, though now this is debated. Some archaeologists believe they are a type of calendar or perform another symbolic function.

The explanatory text struck me as largely conjecture. The comment that sharpening was entrusted to experts is doubtful to me, as well as the idea of a sacred element in sharpening. Such a large stone, out in the open, would suggest a more communal activity, rather than ritual expert use. I’d bet that resharpening, especially stone axes, was a common enough occurrence that anyone using one would have to perform maintenance on the edge. There are many small sharpening stones from the Roman era that have a small hole drilled into them, so they can be carried with the user.

Neolithic Sharpening Stone. Reproduction. Geoparco Del Beigua, Liguria, Italy, 2016.
Neolithic Sharpening Stone. Reproduction. Detail. Geoparco Del Beigua, Liguria, Italy. 2016.

More troubling, is that these grooves don’t reflect the way a stone would wear down during the course of sharpening. If the axe was used in these grooves, it would dull the cutting edge.  Only by twisting the axe (which could account for in the curves of the marks) would it be sharpened.

Another problem is that these grooves would have had to be defined by some other tool before the sharpening began.  A relatively flat area of the stone would be much easier to find and use, it seems, which is the most common shape for sharpening stones. So the idea that these were a type of jig for sharpening — which would also negate some of the need for an expert to perform the sharpening — seems suspect. This was no ancient version of a Chef’s Choice  knife sharpener, which sharpens both sides of the knife at the same time.

These questions aside, what blows my mind is that natural stones are still used by many to sharpen knives. Are sharpening stones the only stone age technology still in common use in the 21st century?





How to Rejuvenate a Glazed-over Oil Stone

Emanuel E. Ericson and Walter E. Burton Carborundum Brand Products for the Home Craftsman. The Carborundum Company: Niagara Falls, NY, 1935. My Collection.

In 1935, the Carborundum Company published a 93 page pamphlet of surprisingly useful tips and assorted product information. It also has a beautiful cover which typographically and color-wise captures the mid-1930’s aesthetic. Carborundum is Silicone Carbide (SiC), the material many (all?) synthetic oil stones are made of, and the coating on many abrasive papers. The pamphlet cost 20 cents in 1937, according to an advertisement in Popular Mechanics.

The next time I purchase an old glazed over oil stone at a flea market, I’ll try the tip below to clean it, which involves heating it to drive out the old oil and swarth.

It also contains good advice concerning the habit keeping tools sharp. Get into the habit and become “cranky”!


Emanuel E. Ericson and Walter E. Burton  Carborundum Brand Products for the Home Craftsman. The Carborundum Company: Niagara Falls, NY, 1935.




Losing It

At Hopes and Fears,  Jared Fischer asks a variety of educators, neuroscientists, and others the question: “How long does it take to lose a skill?”

Most of the answers are theoretical, and the main consensus is that it is dependent on the skill and how it was acquired.  Similar to the ‘you never forget how to ride a bicycle’ adage, crafts and activities that require extensive muscle memory to learn (and the least conscious attention to perform) tend to be the most durable. Many aspects of bookbinding and knife sharpening fall into this category, and these are some of the most difficult skills to initally learn.

It’s a great question, relating not only to the acquisition of craft skills, but the maintenance of them.  Some answers in the article may contain seeds of argument for institutional conservators who feel they are trapped in front of a screen and need to justify bench time. But no practitioners were ask to self-report on their own experience, so I will ask myself.

Q: Jeff, how long does it takes to lose a skill?

A: I usually don’t subscribe to the idea that various crafts and skills sets are so different that there are isolated muscle memories associated with them.  When I teach freehand knife sharpening, for example, I try to emphasize the relationship between sharpening and leather paring: the muscle memory that it takes to hold the knife freehand on the sharpening stone is closely related to the way you need to consistently hold the knife to pare. So in many regards, I think if you are active in some craft activity it can slow the erosion of neglected skills in another.

That said, when I was a kid I tried to learn how the juggle one summer.  It seemed like hundreds of hours were spent, essentially in failure.  But the next summer, I picked up the three balls and for some reason it just worked.  Juggling may be pure muscle memory, since it primarily depends on how accurate you throw the ball.  Now when I try it, I am not nearly as good, but can keep the balls in the air for a short time and suspect if I kept at it could return to a basic proficiency. So in this case, the skill is severely degraded, but not lost.

A dispiriting aspect of this question is that one’s intellectual knowledge of what constitutes skillful performance often increases during the time that the physical ability to accomplish this decreases.

Well worth reading other perspectives:  “How long does it take to lose a skill?”

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