The area is underlain by Lower Jurassic Bonanza Group volcanic rocks and Cretaceous Longarm Formation (Queen Charlotte Group) sediments.
On the H&W 8 claim there is a silica rich knoll in rhyolitic volcanics. Fragments up to 2.5 centimetres in diameter have been noted. The rocks are white to very light grey, hard and intensely fractured. Abundant pyrite occurs in irregular dark grey vesicular masses within the rhyolitic rocks on the west side of a small quarry. This pyritic zone trends 330 degrees and dips 30 to 45 degrees south- west. Possible remnant bedding at the northwest end of the quarry strikes 045 degrees and dips at 20 degrees southwest.
Alteration consists chiefly of silicification with some kaolinization and the pyritization. The secondary silica is partly chalcedony and partly microcrystalline quartz.
No contacts of the rhyolite zone have been observed. Its west end has been inferred to terminate against an east-northeast fault, while the north contact is poorly defined by several scattered outcrops. To the south is Holberg Inlet. The zone is open to the east.
In 1965, 4500 tonnes of rhyolite were shipped to Vancouver by Lafarge Cement of North America Ltd. Based on surface sampling and the inferred boundaries of the rhyolitic rocks, reserves have been estimated to be 2,000,000 tonnes grading 93.45 per cent SiO2 (Assessment Report 8151). Shearer provides a comprehensive history of the area in Assessment Report 27187.
To the west, silica-rich dacite is estimated to contain 15,500,000 tonnes grading 91.97 per cent SiO2 (H&W deposit, 092L 269).
Geological mapping and drill core logging indicate that an intensely altered 20 to 35 metres thick section of rhyolite (identified as white chalky geyserite) overlies a unit of less altered rhyolitic breccia. The white chalky geyserite is of primary economic interest because of its silica and alumina content. The white chalky geyserite is made up of interbedded units of flow banded rhyolite and coarse pyroclastic rocks.
Drilling in 1999, 2000 and 2003, totaling 46 drillholes, and surface assays indicate that 2 sub areas (Area A and B) contain a rough resource of about 5 million tonnes of material grading an average of 83.26 per cent SiO2, 12.90 per cent Al2O3 and 0.08 per cent SO3. A third area (Area C) lies between Areas A and B and may contain a rough resource of an additional 4 million tonnes of silica-rich geyserite but more detailed drilling is required to determine total tonnage and grades. Throughout the property a further 9 geyserite zones have been identified by geological mapping.
In 2003, Electra Gold Ltd. and Homegold Resources Ltd. mined about 30,000 tonnes of geyserite which will be tested at the Ash Grove Cement plant in Washington State.
In 2004, Electra Gold Ltd sold approximately 100,000 tonnes of geyserite as silica-alumina product to Ash Grove Cement Corporation as part of a 5-year contract. The company also quarried and shipped a 7200 tonne bulk-sample of silica product to Lehigh Northwest Cement Limited.
In 2005, Electra Gold Ltd completed its second year of operation with production of about 120,000 tonnes of geyserite. The operation employs about 6 workers.
Amount of silica extracted has not been published.
In the first quarter of 2016 Electra Stone Ltd. continued to mine silica and alumina products, but suspended operations thereafter. The site remains on care and maintenance (Information Circular 2017-1). In March of 2017 the company sold its interests in the quarry to Linceo Media Group, a private company based in Ontario (Electra Stone Ltd. Press Release March 9, 2017).