Herbert Arnold Duke, 84, a former lingerie salesman and amateur gemologist who founded the International Gem & Jewelry Show died March, 6 at Suburban Hospital in Bethesda, Md. He had Alzheimer’s disease.

Mr. Duke had long been interested in rocks and stones. He collected them while serving in the Navy in the South Atlantic during World War II and later was president of the Washington Gem and Lapidary Society.

He was particularly fascinated by fried marbles—glass marbles that are placed in boiling water and then cold water. The cracks form beautiful designs. In the 1960s, he began selling fried marble jewelry while working as the Washington-based East Coast sales manager for M.C. Shrank, a lingerie business.

From the mid-1960s to about 1980, he owned Treasure of the Pirates, a jewelry store in Bethesda that also taught jewelry-making and offered stone-cutting classes.

Mr. Duke started the jewelry show in Washington, D.C., in 1968, and it grew into a booming family business that operates about 90 shows a year nationwide.

He was a native Washingtonian, a 1938 graduate of Roosevelt High School and a 1942 graduate of the old Columbus University. Early in his career, he was manager of the military clothing department at D.J. Kaufman’s men’s clothing store in Washington, D.C.

His wife, Bettye Robinson Duke, whom he married in 1955, died in 1998.

Survivors include three children, Roxane Duke of Potomac, Daniel Duke of Derwood and Arnold Duke of North Potomac; and four grandchildren.

JCK