A STUDY IN MINERALS by Frederick Griggs

Pacific Press Publishing Company · Oakland, California · Jan 22, 1902

A STUDY IN MINERALS.

By Frederick Griggs

The study of stones and minerals is of material interest to the little child. He never goes where they are that he does not gather them. His hands and pockets are full of them. Why does he like them? Because of their form and color; and the small child delights in simply handling them. But this natural interest, like all others, wanes when it is not exercised. As evidence of this loss of interest, I have only to call attention to the well-known fact that very few people indeed know anything of consequence about stones, hardly the names of even the commonest. Could any little stone tell its history, it would be an interesting story. Two stones lying side by side might tell very different stories indeed, as to how they came to be where they are. But all stones would have to agree in one point if they should tell the story of their life; and the point of agreement would be that they all came from under the ground. When the Lord created the earth, He made it very beautiful. The mighty mountains towering toward heaven were not rough and ragged as we now see them, but were rounded and beautiful. Because of sin, the Lord destroyed the world that then was and its inhabitants. He chose a great flood of water as a means of doing this work. The fountains of waters were broken up, and great storm-clouds poured their contents on the earth for many days, continuously. The crust of the earth was broken; mountains disappeared, and others were lifted up where before there were none. Mighty rocks of all kinds were thus brought to the surface, and in place of the even appearance of the earth's surface before the Flood, it became jagged and rough as a consequence of the great force of the waters of the Deluge. So the rocks of the earth, which were formerly hidden beneath its surface, are now visible. This rock formation does for the earth what the bones do for the body; that is, it gives and maintains the earth's shape. It is by the action of the mighty force of the waters of the Flood that great forests were buried beneath the earth's surface. These forests of wood, through the action of the earth, have taken on a mineral form; and the various kinds of coal are given by the Lord for the use of man.

It is not only the action of the waters at the time of the Flood that has brought the rocks which we see to the place where they are, but the centuries of heat and cold and storm have also had a great part in this work. Not only have they had their work to do as to the place where the stones are now to be found, but they have had much to do in the matter of the present shape or form of the stones.

Now in the study of rocks it is not necessary that we should undertake a study of books. We can begin by classifying in a simple manner the stones which we find. They may be classified as to hardness, form, luster, weight, or specific gravity, tenacity, etc. In speaking of this matter of classification I may use some words which may not be familiar to those who have not been studying this subject; but a little use of the dictionary will, I think, make their meaning clear.

I may add here that for many parts of our country this study which I am now suggesting can not best be made at once, because of the condition of the ground. But this subject comes in at this point in this series of science studies, and can be of use a little later to those who have not now collections of stones which can be studied. Many, however, have these collections now in their homes, and to such this study may be an interesting one, even for midwinter. I also want to suggest that a record be kept of the observations made on stones. As I said in the article on meteorological records, the making and keeping of such records has a great value in itself, if the observer continually aims at accuracy.

While these studies will be of value to the parents and younger children, there are in many homes older brothers and sisters who can take up this work to the profit of the whole family, and at the same time be laying the groundwork for efficiency in teaching others.

In the division of stones as to hardness, we have first those which are VERY SOFT. These can be scratched by the finger-nail or very easily by an iron. Then the soft which can not be scratched by the finger-nail, but may be by a knife. Next the hard, which can not be scratched by a knife, but which will themselves scratch glass. Then the very hard, which will not only scratch glass, but will as well scratch quartz. And lastly the adamantine, which can be scratched only by the diamond and itself and not by any other substance. These divisions are so simple that any child of five or six can readily make the classification, and find pleasure in so doing.

Of the very soft minerals there may be named the Talc and Gypsum; of the soft, the Calcite and Fluorite; of the hard, the Apatite and Orthoclase; of the very hard, the Quartz and Topaz; of the adamantine, the Corundum and Diamond. There are of course many other minerals which might be named and classified according to their hardness. Stones of the same size often differ very greatly in weight, and it is a very profitable feature of their study to weigh them and also to find their specific gravity. The specific gravity of any object may be found by weighing it first in air then in water, and by then dividing the weight in air by loss of the weight in water, for it always weighs less in water than in air.

As to the tenacity of minerals, they are brittle, maleable, sectile, ductile, flexible, and elastic. Few stones possess other of these qualities than brittleness, but other minerals, such as iron, copper, aluminum, etc., possess the other characteristics spoken of. In the classification of stones as to form, they will be found to have surfaces which are grapelike; to be in rounded masses; to be porous; to be composed of small crystals, which are often not seen without the aid of a magnifying glass; to be in layers. There are other forms, but these general ones will suffice for elementary study. The streak or color of a stone can best be found by drawing it over a piece of ground glass or a file. In the classification of minerals as to luster, they are metallic and non-metallic. Of the non-metallic there are pearly, as in the pearl and mica; vitreous, as in glass; resinous, as in sulphur, sphærite, and resins; pitchy, as in cannel-coal; silky or satiny, as in satin spar; greasy or waxy, as in serpentine; and dull, as in chalk.

Generally speaking, I do not believe in emphasizing the matter of classification in science study, for it tends to take the mind away from the life of the object under study to the peculiar form or characteristics which are involved in its classifications; but in the simpler studies of minerals the most natural and effective means is to classify. The habit of observation of minerals thus established will lead to more critical and deeper study.

FREDERICK GRIGGS.

So. Lancaster, Mass.