Rockhound May-June 1973
One Thousand Shades of Chalcedony
By CARL F. HOOTS

 

More than a thousand shades and patterns of both flashy and pastel chalcedony in thumb-sized chunks litter the sandy banks of the White River in the Lake Norfolk area.

For three to four miles on either side of the Missouri-Arkansas state line, the sand flats will produce 100 pounds of tumbling rocks in a short day's work for the rockhound.

This section of the White River is in the backwater of Lake Norfolk, and rises and falls from season to season. This condition, coupled with the backwash from motorboats, exposes a whole new supply of stones each year.

The color range of these conchoidal-flaking gemstones varies from sugar white to coal black. Red is the predominant color, with blues and greens the least found.

Agate-like banded patterns are probably the most unusual of the lot, with hundreds of variations of kaleidoscopic symmetry. And no two are alike as to either color or band pattern.

About 15 percent of the chalcedony of the Ozark area is translucent, especially in the pastel pink and yellow specimens.

Along with chalcedony, the area produces quartzite, novaculite, jasper, prase, sard and carnelian. Many rockhounds lump all of these types into one category, but there is definitely a difference in the material properties and color of each named variety.

What really makes these gemstones so interesting is the fact that they were found and broken into by prehistoric rockhounds who made tools and charms from them as long as 15,000 years ago.

The greatest concentration of colored rocks are found at the Niles Workshop area. This is a prehistoric workshop where millions of silica nodules have been broken, leaving many millions of cores and chips as discard material from the tool projects.

Rarest of the finds of the chalcedony discards are those specimens that contain a small fossil form or a B-B size crystal geode within the cone of rock.

It is believed that the reason so much of this broken stone exists is that early man broke millions of them in search of the rare and unusual. He wanted his personal effects to be unique in his society. Unusual charms and tools gave him a special status among the craftsmen of his cultural group.

It is still a mystery where all of these broken stones originated. But rockhounds should be grateful that their prehistoric kin left these treasures for them—some as plentiful as 20 items per square foot.

Not all of the finds are native to the area. Large Arkansas crystals, Dakota sard, and occasional bloodstones were probably transported into these workshop sites from several hundred miles away.

To prove that these items were handled by prehistoric man, the rockhound has only to examine the chipping on the specimens. As additional evidence of man's early work on these rocks, we find that about one in 24 is a part of a complete artifact.

The best collecting time is the late summer, when the lake shores recede some 15 feet, exposing the workshop sites.

Chalcedony, though not the rarest of gem materials, is in this case beautiful, plentiful, and it requires no strenuous breaking-out or digging to recover it. And, best of all, the finding is easy.