A Legacy Unearthed: The Story of Corona’s Blue Diamond Mine
The story of a significant mining operation in Corona, California, today known in part through the activities of FST Sand and Gravel, is a narrative etched in the very earth of the Temescal Valley. Its origins stretch back to the dawn of the 20th century, a time of burgeoning growth in Southern California that demanded vast quantities of raw materials.
1888
In 1888, the site was initially worked by the Temescal Rock Company, which extracted ballast rock crucial for the expanding railroad network – the framework upon which the entire region’s development was built. This early enterprise laid the groundwork for the more extensive operations that would follow.
1928
Eventually, the Blue Diamond Company acquired the property, recognizing the value of its immense aggregate deposits, which were essential for the concrete needed to construct the buildings and infrastructure of growing communities throughout Riverside, San Bernardino, Orange, and Los Angeles Counties. Under Blue Diamond, the mine became a key supplier of various aggregate materials, large and small, a vital resource for the ongoing construction boom. However, this chapter of the mine’s history was dramatically altered in 1928 when a devastating fire swept through the plant, destroying most of its structures used for processing the materials and forcing its closure. This event marked a significant pause in the extraction activities at the site.
1941
The dormant mine and surrounding land remained in this state until the early 1940s. In 1941, a new era began when 3M (Minnesota Mining and Manufacturing Company) purchased the site. While initially focused on establishing their presence, 3M began manufacturing operations in 1948, shifting the focus of the site’s output. Their work at the Corona location primarily involved the production of roofing granules, utilizing the mined materials in a different, yet equally essential, capacity for the construction industry. 3M maintained a significant operation at the site for many decades, adapting and evolving their extraction and manufacturing processes to the state-of-the-art methods that are now utilized.
TODAY
In time, the quarry operation transitioned again. Today, the legacy of the early rock and aggregate extraction continues, in a larger and more efficient manner, under the management of FST Sand and Gravel and its co-founder, Frank Smith. Operating in the Temescal Valley part of Corona, FST Sand and Gravel continues the long-standing tradition of drawing essential construction materials from this historically significant site, providing sand, gravel, riprap, and aggregate products that contribute to the ongoing growth and development of the region, much as the Temescal Rock Company and Blue Diamond Company did so many years before them. The land, marked by over a century of extraction, continues to yield some of the highest quality materials in the western portion of the United States that continues to build the modern landscape of Southern California and beyond.
