Discovery of a Gerlach Brick

By Dan L. Mosier

In 2006, I was searching through the pallets of bricks at one of my favorite brick haunts, Urban Ore at Berkeley, California. Urban Ore is a recycling store whose motto is “To end the age of waste.” They buy and sell almost anything in an effort to keep it out of the landfill. So I like to support them.

The day I was there, they happened to have a few pallets of ordinary red common bricks in their yard. As I was searching through the bricks, I saw one that was marked with the letters ERL in raised letters inside a rectangular frog. Mortar was covering part of the name. It wasn’t a whole brick. It was missing both ends of the brick. I purchased it along with some other interesting finds.

Part of the marked face of the Gerlach common brick.
Part of the marked face of the Gerlach common brick.

To my surprise, what I had found was a part of a rare GERLACH brick. I didn’t know this until I got home, cleaned off the mortar, and did a search on the letters GERL. When I searched through my database of brick marks and brickmakers, nothing came up that matched those letters. Apparently, the found brick was a sand-molded common building brick not known to brick collectors.

Generally, red common building bricks were not usually shipped very far from the brickyard, because the cost of shipping often exceeded the worth of the brick. So chances are, the brick was made by one of the local brickyards. The letters on the brick did not match with any local brickmakers that I was familiar with and I wasn’t sure what the letters stood for. I recognized that the rock clasts in the brick interior were consistent with the rocks found in certain parts of the San Francisco Bay Area. They were small pebbles of quartz, sandstone, and shale. These constituted about 5% of the porous sandy-clay body. The rocks were similar to what I had seen in other bricks made in Contra Costa County. So that is where I began my search for the maker of this brick.

Gerlach brick interior
Interior of a Gerlach brick showing quartz, sandstone, and shale in a porous sandy-clay body.

John GerlachFirst, I looked in the Mines and Mineral Resources of Contra Costa County, California (Davis and Goldman, 1958) and discovered that there was a Gerlach Brick Company in the list of operators for clay deposits. The letters in the brick fit the Gerlach name, so that was promising. No information about the Gerlach Brick Company was given in that report, so other sources needed to be checked. An online search on Gerlach’s name in the Oakland Tribune newspaper led to a few articles about his brick plant and an obituary for John G. Gerlach, who had died in 1925. The obituary mentioned that Gerlach was a manager for 13 years at the Los Angeles Pressed Brick Company’s brickyard at Richmond, California. He also served as a Richmond City Councilman for six years. He resided in Richmond with a wife and three sons.

In 1914, a building with his name, J. G. Gerlach, was built at 1-5 W. Richmond Avenue in Richmond, made of bricks from the Los Angeles Pressed Brick Company. Gerlach had left the Los Angeles Pressed Brick Company in 1920, and four years later started up his own brick company.

At the Richmond Public Library, I searched their newspapers on microfilm for news about Gerlach and his new brickyard. Here I discovered that his brickyard was located next to the Hutchinson rock quarry in El Cerrito, California. This rock quarry was located on the hill at the end of Schmidt Lane, now occupied by the El Cerrito corporation yard. More information about the brickyard was found in an El Cerrito newspaper and in a couple of clay trade journals, which are listed in the references. It was also mentioned that Gerlach was planning to open a second and larger brickyard at Stege, near the bayshore, but that never happened.

Next, a trip to the foothills of El Cerrito to find the brickyard site had failed. This was partly expected because I did not have an exact location for the brickyard that was somewhere next to the rock quarry. The area was built over by homes and streets, further restricting my search. It is possible that a couple of small pits shown on the Richmond topographic map in the vicinity of Rivera Street may have been the brickyard site. This is on the west side and below the Hutchinson quarry. If so, the yard sat on Pleistocene alluvial deposits that contain sandy clay, which also constitutes the clay body of the brick. Because houses now cover the site, it was not possible to verify the brickyard site. Usually, at the brickyard site, can be found pieces of brick in the soil. This helps to verify the site and the brick pieces should match with the found brick.

The rocks in the area, however, matched with the clasts of quartz, sandstone, and shale seen in the brick. Those were Cretaceous sandstone and shale of the Franciscan Complex exposed in the area. Quartz veins were seen cutting the sandstone in one of the exposures near the rock quarry, which could have been a source for the similar looking quartz in the brick.

Quartz veins cutting sandstone.
Quartz veins cutting sandstone near the Hutchinson Quarry, El Cerrito.

Therefore, the Gerlach Brick Company was probably the maker of the found brick. Usually, I would prefer to compare a sample of a known Gerlach brick with the found brick for verification, but in this case, having the partially marked brick that fits the name along with the match with the rocks found near the brickyard site, indicate that this probably was a Gerlach made brick.

Gerlach had operated his brickyard for only ten months before he died. It was mentioned in 1924 that the brickyard was to install new machinery to manufacture wire-cut bricks as well. If that was done, then there may be wire-cut bricks to be found that should have the same composition as the sand-molded bricks. The bricks were fired in scove kilns and the plant made 30,000 bricks a day. Alameda, Berkeley, and Oakland were the targeted markets. Trucks were used to ship the bricks. The first large order was placed by Rhodes and Jamieson, local building material suppliers in Oakland. The brickyard closed following the death of John Gerlach in August 1925.

The search for Gerlach bricks continue. Evidently, these bricks are relatively rare. The brickyard made an estimated 6 million bricks during its short life. They are likely to be found in structures built from late 1924 to 1926 in the vicinity of El Cerrito to Oakland. With such a narrow date range, this brick can be a useful dating tool for archaeologists if recognized. I’m hopeful that a complete Gerlach brick will be found someday to display here. How fortunate it was that a single marked sample of a probable Gerlach brick was found and saved from the pallets at Urban Ore in Berkeley.


Brick and Clay Record, Clay Products Plant For Stege, Cal., v. 64, no. 7, 1924, p. 518.

Brick and Clay Record, Complete Gerlach Brick Co. Plant, v. 65, no. 8, 1924, p. 554.

Brick and Clay Record, New Equipment Ordered, v. 64, no. 10, 1924, p. 746.

Clay-Worker, 1925, v. 84, p. 646.

Gerlach Brick Company to Reopen, v. 83, 1925, p. 165.

Davis, Fenelon F., and Goldman, Harold B., Mines and Mineral Resources of Contra Costa County, California, California State Mining Bureau, California Journal of Mines and Geology, v. 54, no. 4, 1958, p. 501-583. 

El Cerrito Journal. Gerlach Brick Co. To Build Plant In El Cerrito. September 22, 1924. 

Graymer, R.W. Geologic Map and Map Database of the Oakland Metropolis Area, Alameda, Contra Costa, and San Francisco Counties, California. U.S. Geological Survey Miscellaneous Field Studies MF-2342, 2000. 

Gurcke, Karl. Bricks and Brickmaking. The University of Idaho Press, Moscow, Idaho, 1987.

Laizure, C. M. Contra Costa County. California State Mining Bureau Report 23, no. 1, January 1927.

Oakland Tribune. Former Richmond Councilman Dies. August 8, 1925.

Oakland Tribune. Richmond To Have New Brick and Tile Plant. March 16, 1924.

Richmond Independent, Brick Factory To Start Here. February 26, 1924. 

Richmond Independent, Clay Products Company Formed.  March 3, 1924. 

Richmond Independent, Death Claims John J.[sic] Gerlach, Former City Councilman. August 7, 1925.

Richmond Independent. Gerlach Brick Plant Opened. October 3, 1924. 

Richmond Independent. Richmond Pressed Brick Works Has New Manager; $50,000 Improvement Plan. March 23, 1920.

U. S. Geological Survey. Richmond, California. 1:24,000 map scale, 1947.

Citation: Mosier, Dan L. Discovery of a Gerlach Brick. California Bricks,, 2022.