Leisure hours among the gems

by Augustus C. Hamlin

This remarkable mineral is found in mineralogical specimens in China, Siberia, America, and other parts of the world; but all of the fine gems, with perhaps few exceptions, come from Burmah, Pegu, Siam, lower Bengal, and Ceylon.

The island of Ceylon is the most famous of all the localities thus far known, and it is in reality the most wonderful gem deposit in the world. It was known in the period of the Roman Empire, as the land of the luminous carbuncle. This island, which is situated at the southeast extremity of the peninsula of Bengal, and separated from it by a broad but shallow strait, is about as large as England in its area. In the southern centre of the island a group of lofty mountains appears, rising to the height of about 8,000 feet above the level of the sea. On one side this great upheaval descends in successive ranges of hills until the flanks of the mountains subside into the alluvial plains; whilst on the other side the mountain range is characterized by abrupt precipices sometimes of several thousand feet in height. The great gem-producing districts of the island extend along the base of this mountain range for about fifty miles; and the central and richest part is considered to be located around Ratnapoora, which is scarcely two hundred feet above the level of the sea. This want of elevation in the Ceylon gem strata or placers becomes a marked feature when considering the high plateaux in which the diamond occurs in other parts of the world, also coupled with the fact that the two gems are not found together in the same placers. Here are situated the celebrated mines which have yielded vast quantities of the sapphire, especially the blue variety, for an indefinite period of time. They are not small and trivial deposits, but extend over large areas. Some of the plains which cover the deposits are more than thirty miles in extent, and form a large tract of country. Among them are the Kondapalle, Elk, Tolapella, Horton, Bopatalava, Moonstone, Newera Ellia, and many others.

The amount of labor expended in excavations on these plains is stupendous, and evidences still remain which indicate vast operations and remunerative labor in far distant times. The eastern portion of the plain at Newera Ellia furnishes a good example of the extent of the explorations. This region is still called the vale of rubies, and was mined on a grand scale by the ancient kings of Kandy. Many acres of this plain have been completely upturned, and the surface is still indented with numberless pits of large size, varying from three to seventeen feet in depth. The period of these extensive operations is unknown, and is so far distant as to be beyond the mention of history or tradition.

Most of the gem-bearing districts are classed as wild lands, and belong to the English Crown. As yet the authorities have never bestowed a thought upon their value as a source of revenue, and the search for gems is free to the world. Although much territory has been mined in a rude manner in past times, the fields are by no means exhausted, and offer excellent inducements to skilled labor. If some of the energy and determination now exhibited in the South Africa diamond mines could be transported to Ceylon, the gem marts would soon display the splendors of ancient times.

Ratnapoora, which is the gem mart of Ceylon, and situated in the midst of the mines, means literally the city of rubies. The mines adjacent to it and in the district of Saffragan are the principal ones now worked in the island, but the gems are found under the western plains that extend from Adams Peak to the sea. The plains and valleys southeast of Ratnapoora are all gem fields; and the beds of the torrents sometimes contain so great a quantity of broken fragments of sapphire, garnet, zircon, etc., that the sifted sands are used by the lapidaries in polishing gems.

The mining operations are generally carried on by the native Cingalese, who labor in the light of a pastime and only during intervals of their agricultural employments. Some few, however, undertake the labor as a regular business, but they belong to a low and dissipated class, and do not work systematically or with regularity. Therefore, the gem-mining of Ceylon cannot be regarded as a fixed and permanent business.

When an exploration has been determined upon, a small party of villagers set out for the promising region provided with the implements of mining and the means of camping out. The times selected for the operations are after the heavy rains which prevail in June and October, and the floods have subsided. The beds of rivers or smaller streams are often chosen as easier of access than the plains. If the river-bed is selected, the first act of the explorers is to seek for the proper locality where the gem-bearing strata may be found. To ascertain this, the Cingalese thrust a long iron rod of ten or twelve feet in length into the earth, and test the nature of the sub-soil. By means of long practice, the natives can adroitly penetrate the earth to a considerable depth, and, by the resistance to the movement of the rod, can detect the gem deposit of which they are in search.

If the indications are good, the natives proceed to build a hut if they are at a distance from their village, and prepare for the operations, which often extend over many weeks. After diverting a part of the force of the stream so as to form a quiet pool, they proceed to excavate the sand and gravel within a certain area. In order to accomplish this they use hoes with handles fifteen or more feet in length. The top strata are hurriedly raked up and thrown away; but as the pit deepens and the gem stratum is approached, the work is performed with greater care. As soon as the hoes bring up fragments and bowlders of white quartz, or strike a thin ferruginous crust, every particle of the gravel drawn up is carefully preserved. The gravel and sand thus obtained are then placed in large baskets woven of split bamboo and shaped to a conical point at the bottom. The basket thus filled is placed in the current of water, and its contents washed by imparting to it a circular motion. This washing process is kept up until the stones, gravel, and lesser particles are cleansed. During this operation the gems, which are much heavier than common stones, settle at the bottom of the basket, and are there collected together, so that when the superincumbent gravel is removed, the sapphires, garnets, zircons, etc., are easily discovered at the bottom and removed. This is the manner in which the wet diggings are carried on, and is the easiest mode of exploration; but it is by no means as sure or often as profitable as the operations in dry ground on the river banks or in the plains. The dry diggings are much more laborious, as the soil is firmer and the gem strata must be transported to water to be washed and sifted. These dry deposits are found the richest beneath the alluvial plains, which seem to have been in distant times shallow lakes and lagoons.

The gem stratum called mellan is always well defined, and occurs at a certain depth, which seems to correspond to the bottom of the lake at a definite period. This depth varies from two to twenty feet, and is perhaps even greater; but the natives rarely excavate below the depth of twenty feet. This peculiar formation, which is generally horizontal, is composed of a conglomerate of quartz gravel resting upon or mixed with a stiff clay, often indurated by a ferruginous oxide. In among this cascalho, or just below it and adhering to it, are found the fine pebbles and crystals of sapphire, tourmaline, garnet, zircon, spinel, and chrysoberyl. Under these rocks and in peculiar hollows in the plastic clay, which the natives call elephants’ footsteps, the gems are found clustered together heterogeneously, and often so perfect in form as to appear as though created there. At other places they are collected together in these pockets in such a manner as to suggest the idea that they had been washed in by a current of water.

All these varieties of gems, some of them widely differing from each other in composition and form of crystallization, are here embedded together, and seem to have one common origin. This is the true matrix, and the gems are not found in other portions of the soil unless some disturbing force has removed them, like a strong current of water breaking up the cascalho and transporting the gems to alluvions of its own deposit.