In seventeenth century Denmark there seems to have been no lack of “magic stones,” for it is related that one day as King Christian II was strolling along the beach, he picked up a shining pebble by the aid of which he could render himself invisible at will. Similar power was said to exist in stones that could be found in ant-hills if hot water were thrown onto them on St. Walpurgis Day, or St. Hans’ Day. The Danes of the time also shared in the belief that the stone from the lapwing preserved from illness and sorrow as did the “swallow’s-stone” as well.[[36]]
It has frequently been maintained that the source of pebbles could be broadly determined by their form and surface; for example, well-rounded specimens of fairly uniform size would be classed as marine pebbles, while river-pebbles would be subangular and usually flat; pebbles of glacial origin, on the other hand, would have faceted, rounded edges, their surfaces being polished and striated. However, although these rules might hold good in many cases, careful observation has demonstrated that pebbles of all these supposedly distinct types can be found among those of marine, fluviatile, or lacustrine origin. This is explicable by the fact that while the constant, unhindered action of sea or river would probably produce pebbles of distinct type, the local conditions often interfere with this. For instance, on a low sea-coast, with weak wave-action, pebbles frequently became buried in the sands, thus retaining their form practically unchanged, and even where the waves are stronger, so that the pebbles are more or less constantly exposed to their force, it must be borne in mind that some of these coast pebbles have been swept down by rivers, or have already been affected by glacial action. In these cases the force of the waves will indeed modify the form, but along the lines of that already produced by the earlier agencies. Broadly stated, those that were round or oval would generally remain so, rectangular fragments might have their angles worn away and become elliptical, while flat fragments would not exhibit any notable change in shape.[[37]]
When a group of pebbles have been long exposed to attrition by the waters of a powerful stream, especially where the current is intermittent, and where a large quantity of sand has been worked or blown into the stream by freshet or wind storm, they may become rounded by the erosive action of the water or by the abrasive power of the sand, as well as by the attrition consequent upon their sharp contact with one another. This is exemplified in the case of boulders in a river bed, it having been noted in certain streams on the Navajo Reservation that while the upstream sides of the boulders were polished and rounded, and even sometimes faceted and etched, but little change was observable on the downstream sides. This has been tested experimentally, holes an inch in depth having been drilled in opposite sides of sandstone boulders, and on examination five years later in five different localities where this had been done, the deepest hole remaining on the upstream sides measured but four-tenths of an inch, while in one locality the holes had entirely disappeared, and yet so trifling was the effect of the water on the downstream side that a blue-pencil mark had not been washed away. Of course, the erosion of quartzite and limestone boulders tested in this way proved to be a much slower process, amounting to less than one-hundredth of an inch annually. Another important consideration in the shaping of pebbles by river-water is the swiftness of the current, it having been noted, for instance, that those which have been washed down the steep slopes of the Navajo Mountain and the edge of the Black Mesa are somewhat better rounded than those that have been borne along for a much greater distance by less swift-flowing water.
That striated, faceted, or polished pebbles are always of glacial origin, or that those of glacial origin usually offer these characteristics is far from the fact; indeed, it may rather be said that they are generally missing. The fluvio-glacial drift is much more widespread than ground moraine, and the pebbles found in the former rarely present these aspects; indeed, it has been noted that in an hour’s search through the glacial drift of Connecticut, only a single such specimen may be met with. On the other hand, many pebbles of this type have been found under conditions plainly showing that the striation was due to other causes, in some instances, as with those occurring in conglomerates, to pressure and differential movement.[[38]]
The burying of white stones or lumps of quartz with the dead was not infrequent in early times in Ireland. The peasants of the north of Ireland call these Godstones. A cist found at Barnasraghy, County Sligo, was nearly filled with quartz pebbles, and not long since a white stone was found in a primitive burial place near Larne, County Antrim. That this was a usage confined to the earlier period of Irish history is generally admitted, and the discovery of such white stones in a grave is accepted as an indication that it belongs to an early date.[[39]]
It has been suggested that these white stones were used for burials because of the symbolic meaning of the color, which to the minds of many primitive peoples was that of purity, as indeed it is still among most modern peoples, although the symbolism may not always be consciously accepted. White marble seems to most of us the most appropriate and beautiful stone for monuments, and if to a very considerable degree granite is now used as a substitute, this is principally because of its greater resistance to the deteriorating effect of atmospheric changes. Already in prehistoric times, the cave-dwellers showed a fondness for gathering quartz crystals and fragments, and specimens of those taken from the Auvergne Mountains have been found in the cave-dwellings of Les Eyzies; they may have been used as amulets or talismans.[[40]]
A legend of the great Irish saint, Columba, gives an instance of the curative use of white pebbles. After this saint had vainly entreated Broichan the Druid to free a Christian bond-maiden, as a last resort he menaced the druid with approaching death. The prediction or curse was speedily on the way to fulfilment, Broichan sickened unto death, and in his terror consented to free the maiden. Hereupon St. Columba went to the river Ness and picked up out of its shallows several white pebbles, announcing that they would, by the Lord’s power, work the cure of heathen people. One of the stones was blessed by the saint and placed in a vessel filled with water, on the surface of which it floated, and as soon as Broichan had taken a draught of the liquid he was restored to perfect health.[[41]]
A famous Scotch amulet was a polished globular mass of white quartz, an inch and three-quarters in diameter, owned by the chiefs of Clan Donnachaidh and known as the “Stone of the Banner.” It had been accidentally found by a chief of this clan, who, on his way to join Robert Bruce in 1315, before the battle of Bannockburn, noted a glittering stone embedded in a clod of earth that had become attached to his flagstaff. It was looked upon as a powerful talisman in battle, and water in which it had been dipped was said to cure diseases. Tradition asserted that this white stone of Clan Donnachaidh was identical with that used long before by St. Columba.[[42]] As such white stones were often deposited in graves, sometimes even being placed in the mouth of a deceased person, it has been suggested that perhaps the sparks emitted by the quartz on percussion were believed to shed some faint gleams along the dark pathway of the departed in his journey to the underworld. In Christian times there can be little doubt in regard to the influence exercised by the text in Revelation: “To him that overcometh ... I will give a white stone, and in the stone a new name written, which no man knoweth save he that receiveth it.”[[43]]
Crystal balls are not only valued for the visions to be seen, or supposed to be seen in them, but are sometimes worn as amulets against illness. In some parts of Japan they are thought to ward off dropsy, and their wear is also recommended to guard from all wasting diseases.[[44]] The likeness of rock-crystal to congealed water may well be credited, in the doctrine of sympathy, with its putative power of preventing the watery infiltration from which a dropsical patient suffers. As the Japanese make many choice crystal balls, these objects are generally more or less familiar in that land and have thus appealed as well to those who were superstitious as to those who appreciated things beautiful in themselves.
In Yucatan quartz crystals were not only used for divining, but also to ensure the success of the crops. The fact that such crystals have been found in the Indian mounds of Arkansas, North Carolina, and elsewhere, may warrant the supposition that they had been worn as talismans and then interred with the deceased persons as a most intimate part of their property. The writer’s personal observation in Garland and Montgomery counties, Arkansas, demonstrated that quartz crystals were to be found in mounds together with chipped arrow-points of chalcedony, although the crystals did not appear to have been worked in any way. The region about Hot Springs, Arkansas, has furnished some of the finest rock-crystal found in the United States. From North Carolina also have come many remarkable specimens, the largest of which, found in 1886, was unluckily broken up by the person who discovered it. In its crystal state it must have weighed about 300 pounds, and if cut would have furnished a crystal ball 4½ or 5 inches in diameter. This splendid crystal came from Phœnix Mountain, Chestnut Hill township, in Ashe County, North Carolina, and from the largest fragment recovered, weighing 51 pounds, several slabs 8 inches square and from half inch to one inch in thickness were cut. Nearby a crystal weighing 285 pounds was found, and another weighing 188 pounds. Some of the crystals from this locality had on one side a green coating of chlorite, and when this was not removed, the effect was as though one saw a green moss growing beneath a pool of water. The rock-crystal slabs have an advantage over glass when used for mirrors, as they more truly reflect the tints of a fine complexion. Brilliant crystals from Lake George and its neighborhood have been called “Lake George Diamonds.” In marked contrast with the large examples we have noted, many crystals of quartz are so small that 200,000 would have an aggregate weight of but one ounce and yet many are perfect crystals and doubly terminated.