That Which Sparkles

Figure 1

Lately, while taking my dog on one her numerous walks, I have been noticing an increase in the sparkles on the the side of the road and on the lawn near the road.  Notice the center of figure 1. There has always been a few of these tiny shiny fragments but not this much.  Even when I walked her in the dark with my headlamp, the reflection was quite impressive.  My hypothesis is the town has a new source for their winter salt-sand mixture, one that has a high mica content, or more specifically muscovite (the mineral responsible for the sparkles).  Of course to check this I would have to contact the town and they might think I am nutcase and also who has the time for that.

Muscovite, (KAl2(AlSi3O10)(F,OH)2) is a soft, platey, silicate mineral common in granitic type rocks.  Flat, sheet, or platy silicate minerals are classified as phyllosilicates.  Muscovite is colorless but can be lightly shaded green, brown, yellow, or even red unlike the other main mica, biotite (K(Mg,Fe)3AlSi3O10(F,OH)2), which is dark or black. Notice Figure 2 on my son's hand.

Figure 2

If you are still interested in muscovite you might be a closet geologist and I recommend reading a mineralogy textbook.  One last thing, the name muscovite comes from the use of the mineral for glass in Russia.

Figure 3