RED CINDERS

                            

WHAT ARE THEY?

Red Cinders are the shale, sandstone, clay and siltstone, fired red by the intense heat from burning in old coal slag piles. We screen and crush red cinders into two primary sizes: 3/4” red cinders and 1/4” red cinders. Both products weigh approximately one ton to the cubic yard, but can very with the season. The 3/4” or coarse red cinders is used primarily for driveways and decorative landscaping. The 1/4” or fine red cinders is used primarily for walking paths and running tracks. We also carry 3/8" red cinder chips, a 1”-3” cinder rock, larger clinker boulders and other lightweight cinder products for specialty fill jobs. All products are available on a U-haul or we deliver basis.

WHERE DO THEY COME FROM?

The story of red cinders began over a century ago when miners came to Black Diamond in search of coal. They found millions of tons of the black colored “diamonds” needed by the growing cities of Seattle and San Francisco. In the early days, the miners sought only the purest coal of highest quality and discarded everything else. Unfortunately, the coal seams were not pure, but contained veins of lower quality coal, shale, sandstone, clays and other minerals. These other materials were often referred to as slag. From the underground mines, small rail cars brought the coal and slag to the surface. There, the outside miners separated the good clean coal from the lower quality coal and slag. The top quality coal was sold while the waste slag was dumped in large piles adjacent to the mine portal. Through a process known as spontaneous combustion, the piles caught fire and burned for years. Once burning, the slag was nearly impossible to extinguish and the piles smoldered for years at temperatures exceeding 2,000° F. The intense heat from the burning of coal fused the shale, sandstone, clay, and silt together while iron pyrites found in the famous McKay coal seam caused the burned slag to turn red. This giant “oven” has been compared to the brick-making process so our red cinders often are referred to as “nature’s brick”.

The circumstances which led to the creation of red cinders will almost certainly never be repeated. Today, all the mined coal is valuable, hence very little burnable coal is discarded with the slag. Strict mining laws prohibit the creation of large waste piles in order to prevent the spontaneous combustion of slag. The red color was provided by a special bed of coal known as the McKay and this seam has been fairly well depleted. The red cinders we have today, though a wonder to behold and a great landscaping material, will last many more years but will eventually be exhausted. Our durable red cinder rock has a unique history, yet has found a second life in running tracks, driveways, flower beds and landscapes throughout the Puget Sound area.