April 14, 1895, died #OTD James Dwight Dana. American geologist & zoologist, best known to students thanks to his books "System of Mineralogy" & "Manual of Mineralogy."
His manual is still a standard college textbook in the U.S. and has been continuously revised and updated by a succession of editors.
Dana's "System" proposed to classify minerals based on their chemistry, beginning with native elements and ending with complex silicates 💎
#MineralMonday

https://en.wikipedia.org/wiki/James_Dwight_Dana

#Minerals #Rocks #Geodes #Quartz #Iowa

Happy #MineralMonday! (Not sure if that’s a thing😀).

Behold a Keokuk Geode collected by me in the sunny days of my youth!

We used to ride our bikes across the Mississippi River bridge to a small stream on the Illinois side. The geodes were in the stream and in the exposed dirt of the stream bank.