The DeLamar Mine was an
open-pit silver and gold mine in
Owyhee County in southwest
Idaho, which operated from 1977 to 1998. John Guilbert and Charles Park, Jr. have described the DeLamar mine as "the first modern open-pit silver mine."
It is located about one mile from the
ghost town of
De Lamar, Idaho
De Lamar (also DeLamar) is a ghost town in Owyhee County, Idaho, United States. Its elevation is , and it is approximately west of Silver City. The community lies within an area governed by the Bureau of Land Management.
The community formed ...
, which had been a mining center in the late 19th and early 20th century. The mine was under construction from 1975 to 1977 and began operations in 1977; the first extracted silver was poured in April 1977.
The mine employed 125 workers when it opened, with the bulk of its workforce living in
Jordan Valley, Oregon, around 18 miles away.
At the time of its closure in 1998, the mine had five major pits and was owned by
Kinross Gold Corporation Kinross Gold Corporation is a Canadian-based gold and silver mining company founded in 1993 and headquartered in Toronto, Ontario, Canada. Kinross currently operates six active gold mines, and was ranked fifth of the "10 Top Gold-mining Companies" o ...
.
The mine involved extracting ore from the Silver City
rhyolite
Rhyolite ( ) is the most silica-rich of volcanic rocks. It is generally glassy or fine-grained (aphanitic) in texture, but may be porphyritic, containing larger mineral crystals (phenocrysts) in an otherwise fine-grained groundmass. The mineral ...
, a mineral formation generated by
Miocene-epoch volcanic activity. The silver was primarily in the form of
naumannite
Silver selenide (Ag2Se) is the reaction product formed when selenium toning analog silver gelatine photo papers in photographic print toning. The selenium toner contains sodium selenite (Na2SeO3) as one of its active ingredients, which is the sourc ...
.
Federal inspectors reporting on the mine described the silver as occurring in "an unusual form of disseminated silver locked in tiny particles within soft clay and hard, siliceous
volcanic rock."
In 2017, Integra Resources Corporation acquired the DeLamar Gold and Silver Project in the hopes of finding and extracting additional precious metals on site.
References
{{coord missing, Idaho
Silver mines in the United States
1977 establishments in Idaho
Kinross Gold
1998 disestablishments in Idaho