Massive quartz boulders cover the foreground in this view of the Sierra Estrella, near Phoenix, Arizona.

   No, it's not snow! Massive quartz outcrops in this southeasterly-looking view from Quartz Peak (elevation 4052 feet, 1235 meters) in the jagged Sierra Estrella (Spanish for "Star Mountains"), just southwest of Phoenix, Arizona. This quartz formation is called a pegmatite, and it provides stark contrast to the darker rocks that make up this entire group of mountains. Pegmatites can be rich sources of gemstones and other valuable minerals, but this one is not -- we have looked!
   The high peak with a shaded summit is Montezuma Peak, elevation 4354 feet, 1327 meters. To the left and out of this picture, the South Mountain is visible as a long, rounded ridge, lower in elevation.
   Next View >>

   See the GeoHistory page if you want to know more about why the landscape looks the way it does, or return to the map of "The Rocks of the Valley of the Sun" for more view locations.
   You can also send this as an E-Postcard to your friends!

There are 5 views in this sequence, some from the Sierra Estrella, and some from South Mountain.

You can also view these mountains from space, in a NASA photograph, outside this sequence.

And you can see them far in the background from Lookout Mountain, in Phoenix, also outside this sequence.

to our
FREE monthly newsletter about all kinds of rocks.