Journey to the Pegmatite Mine
This weekend we visited an old San Diego California area pegamite mine that is on a friend of a friend’s property. The owner’s name is Lindsy, he is a heck of a nice guy. Top left photo shows him and 2 of his 3 beautiful nosy dogs on the gentle dirt road leading to the mine. His property is wild and beautiful with a natural spring that trickles mineral rich drinking water year around.
Because the soil is most in that area, lush plant life also grows. Sesame Pooch likes to wander under the wall of sharp edged pampas grass looking for squirrels. Pampas grass is an ornamental type of grass that has escaped into the wild and chokes out many native plants. Each blade has sharp edges that will quickly cut open any exposed skin that touches it, but the dogs’ fur seems to protect them from injury.
The land was serene and relaxing and the weather a near perfect calm 70 degrees, but our ultimate goal was to dig into the pegmatite area. Here you can see my friend Dave using his electric jack hammer powered by large batteries to loosen some of the larger rocks overhanging the pegmatite area.
Pegmatites are extreme igneous rocks that form during the final stage of a magma’s crystallization. They are valued because they are typically made of crystals that are 1 cm long or longer and sometimes contain very valuable rare minerals as well. Our area of San Diego is famous for its pegmatites that come out of the granite rock and if you are lucky, you might find kunzite, quartz, tourmaline and/or various beryl crystals in one of our pegmatites. More common are lots of large mica flakes, black tourmaline (known as schorl) and sometimes we also find large areas of lavender lepidolite.
After some work, Dave was able to loosen the large man sized overhanging boulders shown in the above photo and he stepped back quickly to let them crash down where he had been previously standing. Yes, this dangerous, and I recommend you don’t do it! Here you can see the boulders after they have already fallen with Dave working to make them smaller so we can move them out of the way.
Under those large boulders, we had found some large chunks of quartz, somewhat milky in color with thick streaks of glass clear quartz in areas. The quartz here is unusually glassy and shiny for quartz even when not polished. It’s also unusually sharp! I cut myself several times and bled more than a few drops on the ground before realizing I really needed to get out my gloves. Here you can see some of the pieces I selected to take home.
We have only just scratched the surface on this pegmatite. Below ground might lay untold riches of expensive rare gemstones or there may only be a few more pieces of quartz before the pegmatite runs dry. No one knows for sure and this is part and parcel of the giant gamble known as mining!