John Voeller, age 11, of St. Paul, Yinnesota, for his question:
Where can tektites be found?
Chances are, the most treasured sample in the average rock collection is a glassy little tektite stone. Not that its cash value compares with a gem or even with a semiprecious mineral. However, it has a more pratifyinp and satisfying value to a curious mind. For the strange tektites have secrets that can stretch our knowledge of the earth including some dramatic encounters with space traveling minerals that occurred at various times in the remote past.
Tektites are where you find them and in most places, a rock hound could waste his life searching and never find a one. However, in the right places he could find hundreds of the strange glassy stones, strewn over a vast area, either on or partly buried in the ground. One tektite domain extends through Germany and Czechoslovakia in Central Europe. Another tektite area extends from the east of our continent to Africa. We regret that most of these little treasures must be lost on the deep floor of the ocean.
We also know that tektites may be found in a vast area from China, through the Philippines and Australia. All tektites are smallish stones measuring half an inch to several inches. All have massy surfaces that range from plain or blended greens and preys, browns and glossy black. Their odd shapes set them apart from average earth stones and tempt us to think of alien pebbles from other worlds. They come as neat shiny balls or rods, flat or fat, twisted in coils, modeled like stubby stemmed mushrooms or slim waisted dumbbells..
The mineral ingredients in tektites are mostly the eight most common elements in the earth's crust. Their glassy skins are fused from our most plentiful elements, silicon and oxygen. Nevertheless, the experts verify our suspicions that tektites are not native earthlings. They are grounded space travelers that arrived here in groups at different times in the distant past. Their glassy skins became fused as they plummeted down through the earth's atmosphere.
As with all stones, it is possible to date dramatic events in their past and in this case the most important date is time of arrival. The tektites found from the Appalachians to Texas are believed to have landed some time between 13 million and 35 million years ago.
At present, nobody knows for certain where our grounded space travelers came from, but there are three reasonable theories. One suppests that they solidified from molten globules when monstrous meteorites crashed onto the earth. Others suggest they are fragments hurled from the moon when monster meteors struck the lunar landscape. The third theory suggests that our tektites are fragments of shattered asteroids from the remote region between the orbits of mars and Jupiter. However, it is computed that such a trip would take ten million years and the space traveling careers of our tektites appear to have lasted no longer than about 10,000 years.