San Pedro Valley - Selenite

Cochise College    
Geology of Southeastern Arizona
Geology Home Page

Roger Weller, geology instructor    last edited:  10/13/16

selenite roses
St. David area

Clusters of selenite crystals can be found
in the lake bed deposits near the Apache
Powder plant in St. Davis, near Benson in
Cochise County, Arizona.

The following directions are from another website:

     "This site is based in the hills just west of the town of St. David, Arizona.  The minerals of interest

here are the selenite roses and selenite clusters.  To get to this great spot, take highway 80 that runs

towards Bisbee and Douglas south from Benson.  After going about 5 miles, you will be at a sharp

curve in the main road at which there is a small paved road southbound, marked Apache Powder

Plant Road.  Take this road for 3 miles, where it turns into a dirt road.  The dirt road along here is

not bad, but is a bit washboardy.  After going another half mile, turn right to the west on a road

marked Desert Rose.  You should stay on this road for a little ways until you come to a "T"

intersection, where you should turn right to the north.  This road is not the greatest but you should

be able to make it.  Go a little further and turn let towards the hills to the west.  Work your way until

you can drive right up to the base of the hills, where you can park.

It is not important to go to any special hill, so search around for areas of erosion.  In the softer

eroded dirt that is trailing down some of the hills, you will find the classic selenite balls like you see

in rock shops, ranging from pea-size to golfball size.  Finding large clusters is uncommon, but the

single ones are everywhere.  Remember that the ones you see for sale have edges that look white

because they use a blowtorch on them. 

There will also be chunks of broken selenite which are usually clear with transparent brown mixed

in.  These can be quite neat looking and can range to almost 4 inches long. Last, clusters of of

selenite can be found below the surface in certain areas.  Try to find spots where the ground under

the shallow top soil is a hard, dark, reddish-brown clay-like material.  Pry through it with a

screwdriver and a shovel. Carefully pull out the crystal clumps which are very fragile.  These

resemble the regular selenite roses, but are more transparent and have much thicker blades."