Stilbite

This striking specimen features pearly white, well-formed, translucent sheaves of stilbite arranged in a jackstraw pattern. This specimen, originates from an old quarry in Washington State that supplied rock for the construction of the Skookumchuck Dam in 1970. The presence of zeolites at the site was first identified by Washington State Geologist Ray Lasmanis.

During dam construction (1969–1971), the zeolites were discovered near Tenino and Bucoda, Thurston County. Pockets of exceptionally large mesolite crystals were found early on the north side of the valley, while the south side yielded excellent stilbite specimens during spillway excavation. Some basalt cavities reached up to a meter in diameter, lined with pink to orange heulandite, stilbite, and calcite. Over time, deep orange heulandite faded to light pink after removal from the damp rock. A significant 2-meter-wide pocket of snow-white quartz-mordenite with scattered stilbite was also discovered in the spillway floor. After the dam was completed, a guard floating on the reservoir found a large pocket of exceptional analcime in the north wall. Collecting during construction was highly restricted and was only permitted for the geologist on the project, the dam guard, and a geology student, Rudy Tschernich. Today, collecting is no longer allowed at this locality.

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This specimen comes from the collection of Dr. Peter Tarassoff, a prominent figure in mineralogy, particularly known for his work at Mont Saint-Hilaire (MSH). His diligent collecting and examination efforts have led him to be the first to identify at least 35 species and discover 12 new species, not only at MSH but also at other alkaline localities. Dubbed the "Dean" of Mont Saint-Hilaire collectors, Peter was honoured with the naming of the new species petarasite in 1980. He has authored or co-authored numerous mineralogical articles and has been a member of the Mineralogical Association of Canada since 1964. Additionally, Peter has volunteered at the Redpath Museum for the past 21 years, where he was formally appointed the Honorary Curator of Mineralogy. In recognition of his significant contributions to mineralogy, Peter was awarded the 2017 Pinch Medal