A Priceless Collection of Minerals: To see, or not to see

I was in the field yesterday with my students, and one of our stops was at the California State Mining and Mineral Museum in Mariposa at the south end of the California Mother Lode. I am offering up a selection of photos of some of the finest mineral specimens you will ever see anywhere, but I hope you will read to the end of this post as you look at them. Enjoy!

The first few images are some of the striking specimens of crystalline gold. Gold crystallizes in the isometric crystal system (three equal axes at ninety degrees), but the crystals themselves are rarely seen because gold is so malleable that the structure is lost the moment the mineral rolls in a stream.

Gold crystals, then, instead of gold nuggets. They are just gorgeous, and priceless, because the vast majority of crystal specimens were melted into bullion along with all the other gold during the gold rush days, even the biggest single nugget, one that weighed close to 200 pounds.

 You just don't expect gold to look like this.

Or this...when the Harvard open-pit mine was operating in the 1980's and was about to close down, the miners hit a rich pocket. Mine employees who had hardly ever seen even a small bit of gold in the disseminated ores were surprised to see a 60 pound chunk of gold pass by on the conveyor belt. It was composes of leaf gold, a crystalline variety composed of...um...leaf-like flakes of gold. The entire mass was preserved and can be seen at the Ironstone Winery at Murphys, but a large flake can be seen above.

And then there is the Fricot Nugget. The 13.6 pound nugget is the largest single gold mass preserved from the Gold Rush Days, having been discovered in 1865. It lay a long time in a safe deposit box, almost completely forgotten. It came to the state collection in 1943.

An exceedingly rare mineral is a beautiful blue sapphire-like gem called benitoite. It is found at a single mine in the California Coast Ranges. It was designated the California state gemstone in 1985.

The sample below includes two very rare minerals. The black mineral is neptunite, which is often found in association with the benitoite.

Another unique mineral assemblage in California comes from the pegmatite veins in San Diego and Riverside counties. These veins contain immense crystals of quartz, feldspar, muscovite mica, and a group of rare gemstones, most notably tourmaline. For a time in the early 1920's tourmaline was the most prized gem in China, and many incredible crystals were exported.

Other minerals came to the state from all over the world. Below is a striking example of beryl (aquamarine), a relative of emerald.

And sulfur crystals deposited on aragonite crystals...

And some beautiful crystallized azurite and malachite, ores of copper.

And opal from the Virgin Valley in Nevada...

Another example of pegmatite contains a form of feldspar called amazonite.

Some more spectacular azurite crystals.

The crystals below are wulfenite, an important ore of molybdenum and lead.

And finally, the museum has an excellent exhibit of meteorite specimens, including this cross-section of the crystallized elemental iron of the Giant Goose Meteorite, which fell in Modoc County in 1938. The original weighed over a ton.

Wouldn't you just love to see these incredible rare specimens for themselves? I can assure you that it is a great exhibit, quite worthy of a short diversion on your way to Yosemite National Park. But you don't get to see them. You may never get to see them ever again. Why? Because the California State Mining and Mineral Museum is on the state closure list, one of 70 parks to be closed and shuttered because of cuts of $22 million to the state park system, approximately 70 pennies for each inhabitant of the state. I am incensed that the people of our state legislature are so incredibly short-sighted as to allow this to happen.

I feel hopeless sometimes at the stupidity I see. State parks generate economic activity, they don't drain it. Closing these parks makes no sense at all. Mitchell Caverns has already closed, and vandals have already done grievous damage. It will cost so much more to re-open these parks once they have been degraded. And yet that is what our government has decided to do, come June. I don't quite know what would work to change this, but one can start by letting your legislators know how you feel about this. The parks have few friends in the legislature obviously, but the politicos might listen to someone besides their ever-present lobbyists if they heard from their constituents. Who knows? There is a facebook page for the California State Mines and Mineral Museum, and there is the California State Parks Foundation, the best place to get information on how to proceed politically.

I know that blogs are places for the writing of many words, but I have few enough words that can express my disgust at the members of the state legislature and government for allowing this to happen.

The Other California: The CA State Mineral Museum - this is art, darnit!

I know it when I see it. Purveyors of that which we would not call art would use shiny perfect minerals that would cause the viewer to objectify the image, and desire to possess it without appreciating or respecting the intrinsic value and quality of the mineral. I would never stoop that low just to get readership here at Geotripper. Just ignore the "xxx" and "big gold nuggets" in the blog tags. Besides, these things are in a museum. That makes this art, darnit!

And what a great museum it is! One would think that the official state mineral collection would be housed in the state capitol somewhere, or in San Francisco or Los Angeles. The collection actually was in San Francisco for many years, surviving the 1906 earthquake, but in 1983 the collection was moved to Mariposa in the Sierra Nevada Mother Lode, where it resides in the California State Mining and Mineral Museum, a unit of the state park system. The choice of Mariposa makes a certain amount of historical sense, as the town hosted one of the very first hardrock mines and mills during the Gold Rush, the Mariposa, discovered by Kit Carson and ultimately owned by John C. Fremont, two of the big players in early state history.

One of the premier attractions of the collection is the Fricot nugget (that's a part of it at the top of the page), the largest single remaining nugget from the Gold Rush days, at 13.8 pounds. It sits in a vault within a vault. Most large nuggets were simply melted down (there is a larger nugget at the Ironstone Winery, but it was found in the 1990's at the Harvard Mine). There is a facsimile of the biggest nugget ever found, which originally weighed in at around 200 pounds.

The other smaller gold sample shown above is extraordinary as it shows the crystalline nature of the metal. The mineral forms octahedral crystals, but they aren't seen often because the malleable metal gets pounded into the more familiar nugget shape while being rolled in a stream. Samples like this one have to come from the quartz veins in mines.

The museum has a spectacular collection of other minerals, including some of the best specimens of our state gemstone benitoite. This exceedingly rare sapphire-like crystal is found at a single locality in the world, a serpentine outcrop in the Coast Ranges of San Benito County.

The museum has a host of other minerals on display, like the malachite sample above, and the aquamarine sample below. There are some excellent interpretive exhibits regarding the history and current state of mining in California, and even a 175 foot long tunnel that recreates a gold mine.

Admission is $4.00, but they offer discounts for school field trips (call in advance). The staff and volunteers are knowledgeable and helpful. The museum is located on Highway 49 just south of the town of Mariposa at the county fairgrounds. Unfortunately, the museum has been one of the pawns in the state budget wars, and has been threatened with closure off and on. It could use some friends in the capitol...

The Other California is part of my continuing explorations of the California that you don't always find on the postcards.