A dictionary of Comstock mining terms

As I write my articles each week for the Comstock Chronicle in Virginia City, Nev., I often wonder if tourists to the area and sometimes even local residents know the meaning of some of the terminology we use to describe things related to mining and the Comstock.

With this article, I have compiled a short list of a few words used locally with definitions for those who may be unfamiliar with them.

Amalgamation: The process of using mercury to collect fine particles of gold or silver from pulverized ore. These precious metals dissolve in the silvery liquid, while rock does not. The mixture is later heated and the mercury evaporates off leaving the gold or silver.

Arrastra: A crude drag-stone mill for pulverizing ores containing gold or silver.

Bonanza: The discovery of an exceptionally rich vein of gold or silver.

Borrasca: An unproductive mine or claim; the opposite of bonanza.

Claim: A parcel of land that a person has staked out and legally recorded title for mining purposes.

Claim Jumping: Stealing someone else’s mining property – often after it has been staked out but not yet recorded.

Colors: The particles of gold gleaming in a placer miner’s pan after washing. Sometimes called “values.”

Cornish pumps: Large steam powered pumps used to remove water from the deep Comstock mines.

Crevicing: Removing gold from cracks and fissures of rocks, often in a stream bed, by prying it out with a knife.

Cross-cut: A mine tunnel running across an ore vein, used for ventilation, access and communication between work areas.

Drift: A mine tunnel following the direction or “drift” of a vein; opposite of a cross-cut.

Gallows Frame: A wooden or steel scaffold at the top of a mine shaft carrying the hoisting rope and machinery. Also called “the works.”

Gangue: Worthless minerals mixed in with valuable ore.

Giant Powder: This is what miners called dynamite.

Gumbo: A wet, sticky clay that is a nuisance to mining operations

Hard rock: Ore that could be removed only by blasting, as opposed to being worked with hand tools.

High grading: The theft of the more valuable high-grade nuggets and pieces of ore by mine workers.

Lode: A clearly defined deposit of rich ore. The principal vein in a region is called the “mother lode.”

Muck: The debris left after blasting hard rock. Miners shoveling this ore-bearing material were called muckers.

Placer: A deposit of sand, dirt or clay usually in a stream bed that contains fine particles or nuggets of gold or silver. These particles are washed out of the soil with a pan, sluice or other separating device.

Pyrite: Fool’s gold; a mineral of iron or silicon and oxygen that has color similar to gold.

Quartz: A crystalline mineral often white or semi-transparent in which gold and silver veins are sometimes found.

Salting a mine: The act of planting rich ore samples in an unprofitable mine to attract unwary buyers.

Shaft: A deep vertical or inclined excavation: usually the main entrance of a mine where hoisting works provide access to tunnels below.

Sluice: A wooden trough or box used for washing placer gold. These were sometimes called “long toms.” Ore was shoveled in and a steady stream of water washed away the lighter material while heaver metals settled into cleats known as riffles. Sometimes these were made to rock back and forth to speed up the action and these were known as rockers.

Sourdough: An experienced prospector; usually one who had the foresight to save a wad of fermenting dough to use for making bread.

Square sets: A method of timbering large underground excavations and tunnels to prevent cave-ins. The method used cubical frames of timbers to fill any shape of underground excavation. It was developed by Philip Deidesheimer for the Comstock Mines in the 1860s.

Stamp mill: A steam or water powered device used to pulverize ores into a fine powder by the use of heavy iron stamps rising and falling with the action of a cam. Capacity of mills was determined by the number of stamps they contained.

Toplander: A mine worker who worked above ground.

V-Flume: A device used to transport logs down from the Sierra Nevada forests to be cut into lumber. It consisted of two large planks nailed together in a V shape and supported on trestles or on the ground. A small stream of water floated the logs down the flume to the sawmill below.

Windlass: A horizontal drum with a cable or rope used as a hoist in a mine. Sometimes called a whim.

Widow-maker: A compressed air-drill, used to bore holes for dynamite in hard rock. Prolonged inhalation of the fine dust created by early models caused a deadly lung disease called silicosis.

Winze: A passageway usually connecting two tunnels at different levels.

Dayton’s Rock Point Mill

Rock Point Mill_1

Once the amazing discovery of silver bearing ore had been made on the Comstock Lode, the miners were faced with the problem of how to get the many tons of rich ore processed to recover the valuable silver and gold. Several arrastras were built to crush the material in a circular pit using a heavy revolving stone wheel. This primitive method proved too inefficient for the large volume of material being taken from the Virginia City and Gold Hill mines. Several small scale stamp mills sprang up but there was not enough water in the intermittent springs to operate them on a continuous basis.

The earliest prospectors and miners on the Comstock knew that there were mills in California, so they sent horse or mule drawn wagon loads of ore across the Sierras to be processed. This was at great expense but the ores were so rich, the investment paid off. As the volume of material being removed from the mines increased, it became evident that large scale local mills must be built to handle the demand. The problem was, there was not yet a water system in the Virginia City area that could supply the volume of water required to operate a mill of the size needed.

Rock Point Mill_2

A large number of small stamp mills sprang up along Gold Canyon, Six mile Canyon and around Virginia City and Dayton. These were relatively low production operations and usually processed not much more than one ton of ore per day.

The nearest place where there was sufficient water to operate a large quartz mill was along the Carson Rock Point Mill_3River. The placer miners who had been working along Gold Canyon for several years had constructed a ditch near Dayton to bring water from the carson River to the lower end of Gold Canyon. This same source of water was destined to be the source of water for a thriving new milling operation.

In 1861, the first large scale quartz mill in the region was constructed at Rock Point in the town of Dayton. Water from the Douglas Ditch was diverted to serve the Rock Point Mill and the ore from the Comstock mines could then be hauled down Gold Canyon for processing rather than the expensive journey over the mountains to California. The mill was also used to process much of the ore from the mines at Como and other nearby areas.

The original Rock Point Mill was owned by Hugh and J.R. Logan, James Holmes and John Black. The main building was ninety by one hundred feet with forty-two stamps and could reduce fifty tons of rock per day. It was powered by a waterwheel of one hundred horsepower. During its many years of operation, the mill was remodeled, refurbished and rebuilt several times. For those of you who have never witnessed the operation of a stamp mill, the one thing that everyone who has seen one in operation comments on is the noise the machinery makes as it crushes the ore to a fine powder under the clattering steel stamps.

The mill ran until 1882 when it burned down and was quickly rebuilt. The mill then began receiving ore from the Comstock on the new Carson and Colorado Railroad. It burned again in 1909 and was rebuilt in 1910 as the Nevada Reduction and Power Co. At that time, a new aerial tramway was constructed that carried ore to the mill site from Silver City and Gold Hill.

The 1910 reincarnation of the Rock Point mill was updated with steel and concrete construction. Due to decreased demand for milling in the early 1920s, the mill was dismantled and the machinery was taken to Silver City. Today, the site of the Rock Point Mill is a part of the Dayton State Park. There are extensive ruins that visitors are encouraged to visit and explore on a self-guided tour over well marked trails. It is located on the west side of U.S. Highway 50 across from the park. There is a concrete lined tunnel under Highway 50 for access between the park and the mill site.

The ruins that remain today are massive concrete foundations where the stamping machinery was mounted, stone walls and masonry built by Italian stonemasons, a massive concrete water tower and remnants of roadbeds and water storage areas. The ruins are located in and around a large grove of old cottonwood trees and although the area was used for years as the Dayton town dump, there is no trace of this unless you know where to look. There are two interesting rooms or rock tunnels carved into a hillside that were probably used for storage of explosives or flasks of mercury. These are safe to enter since they are carved in solid rock with no danger of cave-in.

After construction of the Virginia and Truckee Railroad through the Carson River Canyon between Moundhouse and Empire City in 1869, there were many more large mills constructed in that area. With the reincarnation of the V & T to Carson City, visitors can view the sites of these mills from the train as it passes through this extremely scenic canyon.

Related: The Remains of the Rock Point Mill