People have been searching the stream gravels of Idaho for garnets since the late 1800s, but commercial production did not begin until the early 1940s. At that time, thin gravel layers in the sediments along Emerald Creek, Carpenter Creek, and Meadow Creek in the Idaho panhandle were being mined for garnet abrasive.

The gravel layers containing the garnet were only a few feet thick, but they consisted of up to 15% almandite garnet by weight. The garnets ranged from sand-sized up to over two inches in diameter. They were being weathered from mica-garnet schist in the upper part of the drainage basins.

Most of the garnets in these sediments were not gem quality. They were mined and crushed to produce garnet abrasive granules. At some operations, gem-quality stones were picked out by hand before crushing. The deposits were worked from the 1940s through the 1980s and were an important source of industrial garnet in the United States at that time. Today, most abrasive granules used in industry are manufactured materials rather than natural materials. It is unlikely that garnet mining for abrasive use will return to Idaho in the future.

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