Richard H. Sioui, Ph.D, age 88, died peacefully on Saturday, June 13, surrounded by his family. He is predeceased by his beloved wife of 54 years, Mary Ann (Kapinos) Sioui.

Richard is survived by his children, Kathleen Sioui of Burnsville, North Carolina, Thomas Sioui and his wife, Janice, of Boylston, Daniel Sioui and his wife, Margaret, of San Diego, California, Rebecca M. White of Oxford, Linda M. Koceniak and her husband, Jamie, of Castro Valley, California, and Michelle M. Bernier and her husband, James, of Somers, Connecticut; thirteen grandchildren, Jocelyn and Tamara Sioui, Danielle, Joseph, and Pavel Sioui, Zachary and Joel White, Garrett, Genevieve, and Adam Koceniak, and Katherine, Matthew, and Alicia Bernier. Richard leaves one sister, Wanita Laffond, and is predeceased by his sister Linda Harrington, his wife of 2 years, Signe (O'Donnell) Sioui, and his son-in-law, Scott F. White.

Born in Brooklyn, New York, on September 25, 1937, he was the son of the late Joseph F. and Ellen (Johnson) Sioui. He grew up in Springfield and Holyoke and resided at the Brightside Orphanage from 1946 to 1949. He graduated from Cathedral High School in Springfield and served honorably in the United States Air Force from 1955 to 1959, receiving the Good Conduct Medal.

Following his military service, Richard attended Northeastern University, where he earned a Bachelor of Science degree in Chemical Engineering. He continued his education at the University of Massachusetts Amherst under a National Science Foundation Fellowship, earning both a Master of Science degree and a Ph.D. in Chemical Engineering. His doctoral dissertation focused on liquid fuel combustion. During his academic career, he was elected to the prestigious honor societies Tau Beta Pi, Phi Kappa Phi, and Sigma Xi. He also completed studies at the School of Industrial Management at Worcester Polytechnic Institute and the Tuck Executive Program at Dartmouth College. In 1995, he received the Outstanding Engineering Alumnus Award from the University of Massachusetts School of Engineering. He was also a longtime member of the American Institute of Chemical Engineers.

After completing his studies, Richard joined Norton Company in Worcester as a Senior Research Engineer. During his distinguished 32-year career, he advanced to become Director of Superabrasive Technology and later Research Director of the Superabrasive Division. His work afforded him opportunities to travel extensively, visiting more than 30 countries and circling the globe three times. Among his favorite destinations were London, Paris, and Tokyo. Widely recognized as an authority in industrial diamond and cubic boron nitride technology, Richard was awarded nine United States patents and numerous foreign patents. He was listed in Who's Who in America and American Men and Women of Science and served on the Safety and Standards Committee of the Diamond Wheel Manufacturers Institute. Dedicated to education, he also established a faculty award within Northeastern University's Chemical Engineering Department to encourage excellence in teaching.

Richard maintained a lifelong commitment to Scouting. He earned the rank of Eagle Scout and was inducted into the Order of the Arrow during the 1950s. Throughout the 1970s and 1980s, he served as Assistant Cubmaster for Pack 180 and as Assistant Scoutmaster and Committee Chairman for Troop 178, both in Holden. Following his retirement, he continued his service to Scouting as a Roundtable Commissioner, District Chairman, and Unit Commissioner with the Nashua Valley Council. His many Scouting honors included the District Award of Merit, the Silver Beaver Award, and the Bronze Pelican Award. Richard also served for several years as president of the Lovewell Pond Sporting Club.

Richard was especially proud of his Native American heritage. He was a member of the Huron-Wendat Nation of Wendake, Quebec, Canada, and belonged to the American Indian Science and Engineering Society. He took immense pride in the accomplishments of his children and grandchildren and often remarked on how greatly they had enriched his life.

Calling Hours will be held on Wednesday, June 17, 2026, from 4:00 p.m. to 7:00 p.m. in the Boucher Funeral Home, Inc., 110 Nichols Street, Gardner, MA.

Funeral Services will be held on Thursday, June 18, 2026, from the funeral home with Mass at 12:30 p.m. in Annunciation Parish, 135 Nichols Street, Gardner, MA. Burial with Military Honors will follow in the Massachusetts Veterans Memorial Cemetery, 111 Glenallen Street, Winchendon, MA.