Pylotte hastened to explain.
"A natural diamond, Mr. Carter, is pure carbon, crystallized under enormous heat and pressure in the bowels of the earth."
"I am aware of that."
"Charcoal and graphite are also pure carbon, but not in a crystallized condition," continued Pylotte. "If that condition could be imparted to the substances mentioned, we should have the artificial diamond."
"How may that be done?" inquired Nick.
"By subjecting the substance to the same condition under which the natural diamond was crystallized."
"Heat and pressure?"
"Precisely," bowed Pylotte. "Attempts to thus manufacture diamonds have frequently been made. A Mr. Acheson, of Pittsburg, while so engaged, and in obtaining graphite from coal by the heat of an electric furnace, discovered that combination of silicon and carbon now known as carborundum, which has commercial value as an abrasive."
"I know about that," bowed Nick.
"Now, then," continued Pylotte, with an unconscious display of enthusiasm; "while diamonds certainly have been made by artificial means, the great difficulty has been that of producing them at a low cost. Moissan, in my country, produced diamonds by heating charcoal and iron to a high degree, and letting the mixture cool under enormous pressure. He succeeded in obtaining very small crystals, or diamonds, but the cost of production made his method impracticable from a commercial standpoint."