Geology Home Page physical geology historical geology planetary gems
Roger Weller, geology instructor
by Rebecca Bowser
ARKANSAS SHARPENING STONES
wood carving by Clay Bowser
In order to carve between the tiny spaces of the detailed flowers
and leaves, Clay Bowser had to keep his wood carving tools sharpened and
polished. When each of his carving tools became dull, he simply rubbed the blade
a few times against a special sharpening stone that honed and polished his
tools. These sharpening stones, which are also called whetstones, are not just
ordinary stones one would find in their backyard, unless this person’s backyard
was in Arkansas, one of the places where the stones are mined. In fact, the
“unique” name geologists gave to this type of sharpening stone is the “Arkansas
Sharpening Stone.” Arkansas sharpening stones are very popular among the
woodcarving community because woodcarvers such as Clay know that these stones
add more life to their woodcarving tools and, unlike electrical sharpening
tools, won’t remove as much metal from the blade. Since Arkansas Whetstones are
rated the best for sharpening metal blades, the question is: What makes these
stones so popular?
Photo by Norse Woodsmith
WHAT IS NOVACULITE?
Black novaculite boulder along stream in the Ouachita Mountains of southwestern Arkansas. Photo by Bill Martin.
What makes Arkansas Sharpening stones so popular for woodcarvers?
The answer is that these stones contain the rare mineral novaculite, which
derives its name from a Latin word, novacula, and is defined as “sharp knife” or
Novaculite comes in different colors. Photo by Diane Rose Angelo
Not only does novaculite “sharpen” knives or woodcarver tools, but also, these rocks have sharp edges when chipped. When a novaculite rock is broken or chipped, it breaks into a smooth conchoidal (shell-like fracture). Native Americans used the chipped pieces to make their razor-like spearheads, dart points, and arrowheads.
Photo of Novaculite Indian Artificats Courtesy of Antique Helper Dan Ripley.
Novaculite is a sedimentary rock composed mostly of microcrystalline quartz and is a recrystallized variety of chert. Novaculite has a hardness of seven, is dense, hard, white to grayish-black in color, translucent on thin edges and has a dull to waxy luster.