Roman numerals.
| I | 1 | IX | 9 | LXX | 70 | D | 500 |
| II | 2 | X | 10 | LXXX | 80 | DC | 600 |
| III | 3 | XIX | 19 | XC | 90 | DCC | 700 |
| IV | 4 | XX | 20 | C | 100 | DCCC | 800 |
| V | 5 | XXX | 30 | CL | 150 | CM | 900 |
| VI | 6 | XL | 40 | CC | 200 | M | 1000 |
| VII | 7 | L | 50 | CCC | 300 | MD | 1500 |
| VIII | 8 | LX | 60 | CD | 400 | MCM | 1900 |
Mathematical signs.
| + | plus. | ~ | difference |
| - | minus. | ∫ | integration. |
| × | multiplied by. | ≎ | equivalence. |
| ÷ | divided by. | : | ratio. |
| = | equality. | ∺ | geometrical proportion. |
| ± | plus or minus. | –: | difference, excess. |
| □ | square. | ∴ | therefore. |
| ▭ | rectangle. | ∵ | because. |
| ∆ | triangle. | ∞ | infinity. |
| ◯ | circle. | ∝ | varies as. |
| ∠ | angle. | √ | radical. |
| ∟ | right angle. | ° | degree. |
| ⫍ or > | greater than. | ' | minute. |
| ⫎ or < | less than. | " | second. |
| ⊥ | perpendicular. |
The following list was prepared in the geologic branch for the use of geologic draftsmen to enable them to select appropriate symbols for rocks that may be referred to in preliminary drawings by name only. For sedimentary rocks dots and circles, parallel lines, and broken or dotted lines are used; for metamorphic rocks short dashes arranged without definite patterns; and for igneous rocks patterns composed of short dashes, triangles, rhombs, crosses, and cross lines. All these patterns are shown in [Plate III].
Sedimentary material.
[Including residual, detrital, eolian, glacial, organic, and chemically precipitated material.]
| Agglomerate. Alabaster. Alluvium. Alum shale. Anhydrite. Apron (alluvial). Argillite. Arkose. Asphalt. Bench gravel. Bentonite. Boulder clay. Brea. Breccia. Brownstone. Burrstone. Calcarenite. Calc sinter. Caliche. Catlinite. Chalk. Chert. Clay. Coal. Conglomerate. Coprolite. Coquina. Detritus. Diatomaceous earth. Diluvium. Dolomite. Drift. Fan (alluvial). Fanglomerate. Flagstone. Flint. Freestone. Fuller's earth. Geyserite. Gravel. Graywacke. Greensand. Grit. Gumbo. Gypsum. Hardpan. Hematite. Infusorial earth. | Ironstone (also igneous). Itacolumite. Kame. Kaolin. Laterite. Lignite. Limestone. Limonite. Loess. Marble (also metamorphic). Marl. Metaxite. Morainal deposit. Mudstone. Novaculite. Peat. Pelite. Phosphate rock. Phosphorite. Phthanite. Psammites. Psephites. Puddingstone. Pyroclastic material. Quartzite (also metamorphic). Reddle. Rock salt. Rock stream. Rubble. Salt. Sand. Sandstone. Selenite. Shale. Silt. Slate (also metamorphic). Soil. Stalactite. Stalagmite. Talc. Talus. Till. Travertine. Tripoli. Tufa (=chemically deposited lime). Tuff (=igneous fragments). Wacke. Wash. |