We may affirm, perhaps, that nature possesses the power to form the diamond to-day, but are the conditions requisite for its evolution present and complete? We will not now attempt to discuss the arguments bearing upon this interesting theme; but we will, however, modestly state that it is our belief that the diamond is the last gem placed upon the earth, and that the period of its deposition was subsequent to the introduction of some of the higher forms of animal life on the globe, and, possibly, since the appearance even of man. CHAPTER II. ANTIQUITY OF THE DIAMOND AS A GEM. It is quite certain that the diamond is not one of the earliest gems known to man, and the facts of the stone not having been found among the ruins of Nineveh or Bassora, the Etruscan sepulchres, or the jewels of the ancient tombs of the Phœnicians of the island of Cyprus, recently explored by Di Cesnola, afford strong presumptive evidence that its discovery dates within historic times. As the gem in its natural state is not often finely crystallized with smooth planes and perfect transparency, like the limpid crystals of quartz, it was probably long overlooked by man, and its adoption in the decorative arts preceded by the bright-colored and softer stones. The rough crystals are not attractive when placed in comparison with many other gems, and their degree of hardness, coupled with their rarity, probably gave them their value among the ancients. We are inclined to think that their use was governed by the fancy of the rich and powerful nobles, and that the emerald and the blue and red stones took precedence in the selection of gems until the art of polishing was discovered. In the time of Pliny the stone was acquired only by the richest of kings; and in the days of Alexander Severus, in the third century, it was remarkable for its price, while the emerald was estimated for its beauty. Lollia, at the Banquet of Caligula, glittering with the spoils of Asia Minor, of fabulous value, did not wear the diamond, so far as we can ascertain. There is evidence to lead to the presumption that the gem was regarded in the early periods more of a curiosity possessing talismanic powers than as an ornamental stone. The famous crown of Chosroes, made in the latter part of the sixth century, and brought to light by Shah Abbas after a thousand years of concealment in an obscure fortress among the mountains of Lauristan, does not contain diamonds among its ornaments, but is incrusted with pearls and rubies. The absence of the stone in this royal tiara, constructed at this early period of time, is certainly significant, and indicates that it was not high in estimation, or that the art of polishing in a definite manner, so as to reveal the hidden splendors of the gem, had not then been discovered.