Ryolite -- Rocks and Minerals Series #1

NOT RECOMMENDED AT NIGHT; THIS AREA IS RURAL RESIDENTIAL AND LIGHTS WILL ATTRACT ATTENTION. STEALTH REQUIRED.

BE SURE TO GET THE SINGLE DIGIT CLUE ON THE LOGSHEET FOR THE ROCKS AND MINERALS SERIES FINAL CACHE.

Welcome to the Rocks and Minerals Series, where you can learn a little about geology and find some caches at the same time. Each of the six caches named after rocks and minerals has a single digit on the logsheet that you will need to find the Rocks and Minerals Final Cache. For example, in the Ryolite cache, the Clue will be R = (some digit); in the Quartz cache, the clue will be Q = (some digit).

The final is at N 38 56.RQA W 105 17.FGP

Here are all seven caches in the series:

Ryolite (GC9NYB3)

Quartz (GC9NYB6)

Agate (GC9NYB8)

Feldspar (GC9NYB9)

Granite (GC9NYB7)

Pitchblende (GC9NYBA)

And then – Rocks and Minerals Final Cache (GC9NYBB)

"Ryolite" is the name of the street; the correct spelling is rhyolite.

From Wikipedia: Rhyolite is the most silica-rich of volcanic rocks. It is generally glassy or fine-grained (aphanitic) in texture, but may be porphyritic, containing larger mineral crystals (phenocrysts) in an otherwise fine-grained groundmass. The mineral assemblage is predominantly quartz, sanidine, and plagioclase. It is the extrusive equivalent to granite.

Magma with the composition of rhyolite is extremely viscous, due to its high silica content. This favors explosive eruptions over effusive eruptions, so rhyolitic magma is more often erupted as pyroclastic rock than as lava flows. Rhyolitic ash-flow tuffs are among the most voluminous of continental igneous rock formations.

Rhyolitic tuff has been extensively used for construction. Obsidian, which is rhyolitic volcanic glass, has been used for tools from prehistoric times to the present day because it can be shaped to an extremely sharp edge. Rhyolitic pumice finds use as an abrasive, in concrete, and as a soil amendment.

Rhyolite is an extrusive igneous rock, formed from magma rich in silica that is extruded from a volcanic vent to cool quickly on the surface rather than slowly in the subsurface. It is generally light in color due to its low content of mafic minerals, and it is typically very fine-grained (aphanitic) or glassy.

Congratulations to Granitegrabber for being FTF !