Illustrated Glossary of Local Mine Related Terms

• Adit: The entrance to horizontal tunnels driven into a hill side to gain access to the mineral deposits is termed an adit.
• Blackjack is a very dark almost black variety of the mineral sphalerite (ZnS).
• Bone refers to a gray brown rather porous variety of the mineral smithsonite (ZnCO₃) it is synonymous with drybone.
• Cave: When most of us see the term cave we think of something like Crystal Lake Cave or Mammoth Cave but to the miners a cave was a segment of of crevice which was generally wider than typical and generally contained ore minerals. Many times the cave was an open space and did have the appearance of the common 'cave' but more frequently when they first encountered such it would have been filled entirely with red clay and ore minerals. At notable example would have been Stewart's Cave.
• Cog Ore refers to the cubs or cubic masses of the mineral galena that was found generally in the soil; this was the primary target of the earliest mining operations.
• Crevice: In the area around Dubuque the Galena Dolomite is broken or cut by a series of generally trending east-west fractures or crevices. These extend the fill thickness of the layer. The ore minerals were deposited along these. 
• Diggings refers to a group of closely spaced surface mines. These were usually nothing more that pits and trenches and generally represent the earliest form or mining.  
• Drybone refers to a gray brown rather porous variety of the mineral smithsonite (ZnCO₃); it is synonymous with bone.
• Heavy Spar is the local term for the mineral barite (BaSO₄) which resembles coarsely crystalline variety of the mineral calcite (CaCO₃) but is much heavier.
• Jack is a general term for any variety of the mineral sphalerite (ZnS)
• Load or Lead (pronounced like 'read' and not like the element (Pb)) was a particularly rich occurrence of ore minerals along a crevice. It would appear that sometimes this name was applied with a whole lot of wishful thinking.
• Mine: A mine would have been any sort of operation where there was an attempt to find and obtain lead or zinc minerals from the soil or rock. Sometimes the name of a mine endured for most of the mining era while other names were ephemeral or even just on paper.
• Mineral Hole was small shallow conical pit dug into the soil in search of mineral, generally cog ore. In the literature of mining in other parts of the United States these would have been called glory holes or prospect pits.
• Opening: A crevice for the most part was only an inch or two wide but at particular stratigraphic horizons the width was much greater, these wider horizons were called openings. In the case of the Level Crevice there were three openings that were actively mined.
• Range: Sulfide minerals were not found everywhere in the Dubuque area but instead in more localized areas called ranges. Pikes Peak Range was the most familiar range and probably the most productive.
• Shaft: A shaft is a vertical entrance driven down from the surface to the mine, cave, or crevice. These were anywhere from 15 feet deep to 200 plus feet deep. Generally they were about five feet by five feet in cross section. View looking up a shaft into Ewing Diggings.
• Spar refers to the coarsely  crystalline variety of the mineral calcite (CaCO₃).

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