Hammer Smash Pegmatites

The other day I went out to an old, famous mineral collecting locality located right in the middle of the Inland Empire(Riverside & San Bernardino), California. The locality is called the Jensen Quarry, and old quarry that has been turned into a beautiful golf course, pictured above.

Now I wasn't allowed on the golf course obviously, unfortunately, but I could get onto one of the hills next to the course which was part of the old quarry too.

Getting there was quite the hike. Looking on Google maps and Earth never really prepares you for what's actually in store for you and this was no different.

I arrived at 7am hoping to beat the heat. As I hit the trail I realized I was in for some serious hiking. Most of my hiking is on old mining roads which switch back and forth, but these paths went straight up the mountain and over it.

Walking up the mountain there was this cool boulder of granite that had split in two.

The peak was in sight just beyond the boulder.

At this point I started to notice tailings all over the slope. They were grossular garnets and calcite, lots of it.

This was interesting. I hadn't planned on finding garnets, but I knew there were skarn deposits in these mountains. A skarn deposit usually consist of calcite & garnets and that is exactly what was there.

It's hare to tell, but that is all calcite with garnet mixed in places. Here is a closer up.

Because I wasn't there for garnets, I just grabbed a piece or two and continued on up the mountain towards the quarry.

As I got to the top of this first peak I found out that the entire peak was calcite. I was pretty taken back by this. You can see in this picture, the ground is solid calcite crystals.

These hills were loaded with minerals and I knew I would have to come back another time to really explore the whole area, but the Golf Course was calling.

I cut back inland to avoid the rising sun and to follow a trail that appeared to go around the mountain, rather than straight up it. It was then I ran into the first pegmatite. It was predominantly quartz with some feldspar and mica.

Pretty cool to see how these weather.

After about 30 minutes of hiking I had made it to a hill overlooking the quarry.

The hill on the right was my destination, while the main quarry containing the really good minerals was center left.

These large boulders of calcite were left behind.

Reaching the face of the upper cut, there are 3 cuts (levels) in total.

And the picking began with this nice calcite specimen.

Next up aquamarine. Appears to be etched.

Blue calcite.

Bore hole.

This could have been a core or a blasting bore. Not sure which one it was. Seems a bit big for a blasting hole, but also big for a core....

I continued along the face of the cut with the beautiful golf course down below.

This was cool to find, a piece of old drill steel left behind in the rock.

Not common, but you do come across these in old mines every once in a while. They are old drill bits used to make the holes to insert the dynamite to blast the rock away. Much more efficient than a sledge hammer.

The veins you see in the rock are calcite.

The rocks on the ground below that drill steel are larger calcite crystals.

I picked up this nice piece of calcite there.

The quarry ended up giving me some interesting mineral specimens to look at and break apart at home. As I was leaving I checked out the very top of the quarry and found this nice calcite boulder which I smashed with the new sledge hammer. It worked perfectly and I was able to bring this home as well as a bunch of smaller pieces.

What that is is calcite with book mica(mica layers stacked up), hematite and small, orange spessartine garnets. They are very vivd in person.

Along with the nice specimens I got a good workout and some beautiful views.

The pegmatites I saw didn't bear any minerals worth taking, but the moutain is loaded with veins so it's possible there are other pegmatites there that still hold treasures. The quarry did hole good minerals though. So I will definitely have to go back out and explore this area further.