Phyllis Rudstrom Brenner, 82, a geologist who worked and volunteered at the Smithsonian Institution National Museum of Natural History for about five decades, died Oct. 2 at the ManorCare nursing facility in Alexandria.

She had liver disease complicated by Lyme disease, said her son David Brenner.

Mrs. Brenner, known as “Flip,” worked for the Smithsonian as a geology technician for about 10 years during the 1960s and ’70s. She remained with the National Museum of Natural History as a volunteer until several years ago, examining fossils and giving lectures to visitors.

Phyllis Marjorie Rudstrom was born in Chisholm, Minn. She received a bachelor’s degree from Carleton College in Northfield, Minn., and a master’s degree from Mount Holyoke College in South Hadley, Mass., both in geology.

She had lived in the Hollin Hills area of Alexandria since 1957. Her memberships included the Hollin Hills Civic Association and the Hollin Hills swimming pool. She was a volunteer gardener at Mount Vernon Unitarian Church in Alexandria.

Mrs. Brenner guest-lectured on paleontology and geology and displayed her mineral collection at community exhibitions in the Washington area. She contributed many of her mineral and fossil collections to the Minnesota Museum of Mining in Chisholm.

 Her marriage to Edgar H. Brenner ended in divorce. Their son Charles “Sandy” Brenner died in 2008.  Survivors include two sons, David Brenner of Ames, Iowa, and Paul Brenner of Irvine, Calif.; a half-brother, Charles O. “Mac” Rudstrom; and two grandchildren.

— Emily Langer