Devil's Gate limestone under cathodoluminescence. Bright yellow and orange areas are calcite and the bright blue indicates trace minerals along the solution seam. Trace minerals left in the seam are heavy metals and other silicate minerals.
"Stylolites Cathodoluminescence under Cross Polarized Light,"
The Hilltop Review: Vol. 10
, Article 8.
Available at: https://scholarworks.wmich.edu/hilltopreview/vol10/iss1/8