ExtraLapis English No. 15 is a tribute to the magnificent minerals of the San Juan Mountains of Colorado. Chapters cover:

History
Geology
The Red Mountain District
Gold in the San Juans
The Camp Bird mine
Quartz in the San Juans
A sketch of collector/dealer Benjy Kuehling
The Idarado mine
Rhodochrosite from the San Juans
The Sunnyside mine
Huebnerite from the Adams mine
Collecting anecdotes and advice
Reminiscences about Ed McDole
San Juans ephemera and memorabilia

As is typical for the series, the production quality is excellent, the photography is beautiful, and the text is authoritative, readable and interesting.