Gneiss, pronounced like "nice" (though I sometimes hear it said as "nize" too), is a common rock formation in our area. It is interesting for it's layers and flowing patterns of color. Most people just call it "granite". That's fairly close as gneiss is a metamorphic rock, and this formation in the picture is one produced from granite. True granite however lacks the layers and is an even consistency throughout.
This gneiss was formed by granite heated until pliable. Next there had to have been some movement in the molten material to create the flowing patterns and layers. And finally, as the mixture of molten granite began cooling it sat layer upon layer, super compressed for millions of years, becoming new stone.
I like seeing the bands of colors and patterns in gneiss. Wet conditions bring those features out the best. Icicles hanging from the stone are like icing on the cake. We have lots of this ice-decorated rock around here, which is always gneiss to see!