Does your “rock” have shallow, oval pits or depressions on its outer surface? Such features are known technically as _piezoglyphs_ (Greek _piezein_, to press + _glyph_, to carve) and popularly as “thumb-prints.” They were formed during the meteorite’s flight through the atmosphere when the softer portions of its outer shell were “eroded” away, leaving small scooped-out places. These pittings are very similar to the prints that would be made by the human hand in a lump of modeling clay or bread dough. In one case, they gave rise to the false idea that the meteorite had fallen in a plastic state and that the imprints had been formed when its finders first pulled the mass out of the ground by hand. If the specimen you have found already has a corner knocked off, do you see specks and grains of metal on the broken surface? Such scattered bits of nickel-iron (not to be confused with the shiny mica flakes often seen in igneous rocks) characteristically occur in the grayish or brownish groundmass of stony meteorites. If your specimen is unbroken, hold it lightly against a spinning carborundum wheel or use a file to grind a small flat surface upon it, and then examine this surface for specks of metal. If the answers to these questions are yes, then there is a good possibility that you have found a genuine meteorite. If meteorites remain buried in the ground for a long period of time, their characteristic surface-features may weather away. Under such conditions, iron meteorites develop heavy-layered coatings of rust (iron oxide) as much as several inches in thickness. If irons stay in the ground long enough, they may rust away almost completely and turn into shale balls, like those found near the ancient Wolf Creek, Australia meteorite crater. (See Chapter 4.) Stone meteorites buried in the ground for any great length of time may disintegrate and become completely unrecognizable as meteorites. The fact that meteorites of all kinds are attacked by weathering has always argued strongly in favor of their prompt recovery. In the case of witnessed falls, prompt recovery is even more important, for only thus can specimens still retaining measurable amounts of various short-lived radioactivities be made available to physicists eager to investigate them with the most modern radiometric equipment. 10. TEKTITES, IMPACTITES & “FOSSIL” METEORITES Before southern Australia was occupied by the white man, the native tribesmen of that region treasured certain small rounded pieces of black glass as medicine stones, rainmaking stones, and message stones. The Wadikali tribe referred to these objects as _mindjimindjilpara_, a word meaning “eyes that look at you like a man staring hard.” The early European settlers of the area called the same black glassy masses “blackfellows’ buttons.” Both phrases applied to objects that modern scientists call “australites,” which are now one of the best known types of _tektites_ (Greek: _tēktos_, molten).