Geology lab tools, built on solid ground
Identify minerals in thin section, read sedimentary structures, solve stereonet and structural geology problems, and practice with worked solutions. Every claim links to its source.
Plane-polarized light
Cross-polarized light
Retardation = birefringence × thickness. Each mineral is marked at its maximum color for the thickness you choose. Tap the color strip to estimate birefringence from the highest color you see.
Quadrant bearings work too: strike N40E with dip 35SE.
One per line, two numbers each (e.g. 040/35 or 40 35). Planes use the notation chosen above.
Point at the net to read trend and plunge.
Lines are written plunge→trend, planes as right-hand-rule strike/dip. Structural geology normally uses a lower-hemisphere equal-area (Schmidt) net, which is also the one to use for counting point density; the Wulff net is the equal-angle version. Sources: Athabasca Univ. GEOL 319 Lab 3 · U. Alberta EAS 233 Lab 3
Source: Waldron & Snyder Lab 1
Use map coordinates (east, north) and elevation, all in the same units, e.g. meters.
Source: Waldron & Snyder Lab 2
Source: Western Oregon Univ. ES406 Lab 3
Source: Athabasca Univ. GEOL 319 Lab 4
Source: MIT OCW 12.113 notes · GW Project 2.4 · Waldron & Snyder 1.9
Builds a set from the topics you've picked, with a blank equal-area net if any stereonet problems are included and the answer key on its own page. Every set gets a code; the same code always rebuilds the same problems and key.
Set code —
Enter the set code from the sheet, then one student per line: a name, a comma, and their letters in order. Use a dash for a blank, e.g. Maria R, BDAC-ABD.
Suggestions appear here with the reasoning and what to check next on the scope to confirm.