Jcpds Xrd Direct

“A mistake,” she said softly. “From 1962. Someone indexed quartz wrong. They swapped two peaks. It was in the database for ten years before someone caught it.”

“What is that one?” he asked.

“In 1938,” she began, “a chemist at Dow Chemical named Dr. J. D. Hanawalt had a problem. X-ray diffraction was new and powerful. You shine X-rays at a crystal, the atoms inside act like a maze, and the X-rays bounce off the atomic planes, creating a unique fingerprint of peaks. Every mineral, every ceramic, every pharmaceutical compound—it has a unique pattern. But Hanawalt had thousands of patterns and no way to find a match. jcpds xrd