Does this rock look familiar to anyone?

[fuss]

I cant figure it out, thinking maybe a rhyolite or something? it is light purple/lavender in color has quartz phenocrysts, yellow calcite? patches on it.

No reaction to acid other than the calcite crystal patches (assuming thats what they are)

between 4-5 hardness

fine grained smooth texture.

rock has no reaction to LW UV light but the calcite? is yellow/green color.

no attraction to a magnet.

streak is white.

I found it in Washington county WI at the site of an old farmhouse that is long since gone.











Thx

 

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[fuss]

pic's #3 and 4 the color is inaccurate its not that blue...must have been the angle of my flash, #1 and 2 are accurate.

 

[fuss]

Confirmed Rhyolite with yellow calcite at a show today in WI.

 

[stdenis_jd]

never saw this thread - yeah it's rhyolite - must have been buried deep enough to form small quartz crystals - rhyolite is the extrusive (surface) version of granite (intrusive - deep level lithification of felsic magma) and usually doesn't have large crystals so it must have been deep enough to form small crystals but not deep enough to form enough large crystals like granite.