"If you still desire to sell. A certified check for the amount is ready for you. Have you brought the opal?"
"Yes. Have you the duplicate? It would be well to compare them before you purchase."
"If you do not mind, I will do so."
Mr. Mitchel turned to his safe and brought out a box which Mr. Barnes thought he recognized. Opening it he drew out a marvellous string of pearls, which he laid aside, while he took from beneath, a velvet case which contained the opal. Returning the pearls to the box he restored that to the safe, which he locked.
"Now, if you will let me see your opal," said Mr. Mitchel, "I will compare the gems."
"Here it is," said Mr. Livingstone, handing Mr. Mitchel his opal.
Mr. Mitchel took the two opals in his hand, and, as they lay side by side, he examined them closely, observing the play of light as he turned them in various positions. To his critical eye they were marvellously beautiful; matchless, though matched. None could see these two and wonder that the old priests in Mexico had searched in vain for a second pair like them.
"Do you know why these opals are so exactly alike?" asked Mr. Livingstone.
"I am not sure," said Mr. Mitchel, apparently absorbed in his scrutiny of the opals. "I have heard many reasons suggested. If you know the true explanation, suppose you tell me."
"Willingly. You will observe that in each opal red lights seem to predominate on one side, while the blue and green are reflected from the other. Originally, this was one great egg-shaped opal, and it was cut in that shape, and then poised in the forehead of a single-eyed idol by the priests of a thousand years ago. By an ingenious mechanism the eye could be made to revolve in its socket, so that either the red or the blue-green side would be visible, as it suited the purpose of the priests, when overawing the tribesmen by pretended prophecies and other miraculous performances. In more recent times, since the advent of the Christians, one-eyed idols are not so plausible, and the priests cut the opal in half, thus making it serve in what may be termed a modernized idol."