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Mariposa Fair 2018

On Labor Day weekend, come and see the California State Gem and Mineral Museum during the Mariposa County Fair.  The Museum will have a free kid’s activity table on Saturday, September 1st,  and Sunday, September 2nd.   At the table, kids can learn about rocks and crystals and win a prize.

Adult admission to the Museum during the fair is half-price, only $2.00, and kids are always free.  Kids can win another prize by completing our rainbow mineral scavenger hunt, inside the Museum.

During summer months, the Museum is open from 10:00 – 5:00, Thursday through Sunday.  Winter hours will be 10:00 – 4:00 beginning 1 October.

We will also be starting a new volunteer training course on September 19th.  The Museum depends on our trained volunteers to provide educational tours to the many schools, community groups and international visitors that come to the museum.  We also need volunteers to help with special events, “mine tunnel” tours, in the museum shop, and as roving docents at special events.  Call or stop in to find out about being a volunteer tour guide at your California State Park, the California State Mining and Mineral Museum.

2017 Gem Show Speakers and Demonstrations


Matthew Wood

Agates have been collected worldwide for thousands of years and used as gems, tools, and even weapons. How agates are formed is still a geologic mystery, but when cut and polished, they reveal an astonishing variety of colors, patterns, shapes and scenes.

Iris Agate (Photo by Matthew Wood)

In recent years, the discovery of exceptional deposits in Argentina, Mexico, Morocco, China, and the United States have greatly accelerated interest in collecting and exhibiting agates. The museum exhibit features fine agates representative of some of the best-known locations around the world.

(Presentation Saturday at 11:00 a.m. in the Museum)

Specimen Gold & Its Forms from Historic CA Mines

Michael P. Hunerlach

California is home to many historic Mother Lode gold mines. The Mother Lode covers a structural trend of gold mineralization almost 200 miles in length and ranges in width from about 16 miles in the North to just under two miles in the South.

44 pound crystalline leaf gold mass (with permission of the Kautz Family)

Along this structural trend the age of the gold mineralization varies some 30-million years. There is also a change in mineralogy and geochemistry of the gold and the rocks hosting the veins in which gold is located. Specimen gold has many forms associated with the change and structure found in several notable mines and Districts along the Mother Lode trend which will be presented in this talk and may be seen on exhibit in the California State Mining and Mineral Museum Collection.

(Presentation Saturday at 2:00 p.m. in the Museum)

Historic Meteorites in California Collections

Michael Santos

Chilkate Meteorite, on display in the California State Mining and Mineral Museum

This 96-pound meteorite was purchased by the State Mining Bureau in June 1881, from Chief Silver Eye at Portage Bay, Chilcoot Inlet, Alaska.  The father of one of the elders of Chief Silver Eye’s tribe saw it fall from the sky, which means that the meteorite probably hit the earth sometime in the 1700s.

John Muir informed the State Mining Bureau about the meteorite, and purchase was negotiated with the assistance of the Northwest Trading Company and Mr. J. M. Vanderbilt.

(Presentation Sunday at 12:00 noon in the Museum)

Formation and History of the Tri-State Rocks and Minerals

Joseph Garcia

Join Ozark Museum of Natural History Curator Jose Garcia in an introduction of the Tri-State Mining Districts and the history that made this one of the nation’s greatest deposits of Zinc and Lead ores.

Fluorite with barite from Elmwood Mine, Carthage County, TN (collection of Nikki West)

Explore the natural history that occurred over eons to produce the eye-catching spectacular minerals of the Tri-State. The presentation will cover the Pitcher, Galena and Joplin Fields, including a brief history, stratigraphy, geography, and most of all the formation and identification of the Tri-State Mining District minerals.

Joseph Garcia is currently the Curator at the Ozark Museum of Natural History (OMNH), having worked extensively in the region in the Cotter Dolomite and the Tri-State Mining Districts.

(Presentation Sunday at 2:00 p.m. in the Museum)

Night at the Museum

Brett Keller’s beautiful mineral display including his wines

Well, Mariposa Chamber of Commerce mixers have seldom been like this. Thanks to Nikki and all the volunteers who made it so successful, especially to those who donated items to the auctions and raffles. Thanks to Kim and Monica for great social media artwork and publicity.  We were all too busy to take many photos, but Monica managed to grab a few great ones.

Museum Entrance
Welcome at the Museum Entrance
BBQ Raffle at NAM
BBQ Kit raffle prize

Links for Research

USGS National Resources:

USGS Library – Links to numerous mineral related teaching aids

USGS FAQs (Teaching Aids)

Life Cycle of a Mineral Deposit  – An example of a Teacher’s Guide for Hands-On Mineral Education Activities, published in 2005


California State Parks Foundation

California and Nevada Earthquakes

Marshall Gold Discovery State Historic Park

Columbia State Historic Park

Empire Mine State Historic Park

Malakoff Diggins State Historic Park

Bodie State Historic Park

California State Mining and Mineral Museum

Yosemite Region:

The CSMMM Facebook Page – Museum hosted

The CSMMMA Facebook Page – Association hosted

Mariposa Museum and History Center

Consortium of Southern Yosemite Museums

 Mariposa State Fair Grounds and Exposition Center

Yosemite Mariposa Tourism Bureau

Mariposa Chamber of Commerce

Mariposa Gem and Mineral Club

Gem and Mineral Information:    To find out anything about almost any mineral  

Mariposa Gem and Mineral Show 2021

The Spring in Mariposa is an ideal time to hold the annual Gem and Mineral show. However, we’ve adjusted to ongoing 2021 health requirements, and the new dates for 2021 are October 30th and 31st.

The “Mountains of Minerals” show serves as a focal point to share mineral specimens from world-wide locations.  Dealers from far and wide gather to share their knowledge and stock of minerals, speakers give presentations on rock and mineral topics, and demonstrations of lapidary techniques are show highlights.

Hosts of the show:

Many details are still being worked out, but again this year the location is the Mariposa Fair Grounds.  This show is usually the only Gem Show in California at that time.  Mariposa is very near the geographic center of California, convenient to central San Joaquin Valley and Yosemite National Park.


This will be the 20th annual show (2020 show was canceled), which takes place at the Mariposa County Fairgrounds, on historic Highway 49, two miles south of the town of Mariposa, or 30 min. North of Oakhurst. Admission is $3 for adults, 12 and under are free. Parking is free!  Show hours are Saturday 10:00 – 5:00 and Sunday 10:00 – 4:00.

A wide variety of gemstone jewelry and rough, breathtaking mineral and rock specimens, fossils, crystals, beads and mineral related crafts of all sorts will be available from our many vendors.

World class gold and rare gemstones are on display in the California State Mining and Mineral Museum, a permanent part of the fairgrounds, open year ’round. California State Parks will offer a variety of children’s activities at the show. In addition to viewing the spectacular California State Mineral Collection, kids can go on a scavenger hunt in the museum and explore rocks and mineral crystals at the touch table. All activities and demos are free.

Several guest speakers and demonstrations will be on the schedule. Last year we had speakers on Saturday at 11:00 and 2:00, and Sunday at 12:00 and 2:00.

Dryhead Agate (Photo by Matthew Wood)

Our speakers addressed Toxicity in Rocks and Minerals (“rocks you should not lick”) and California gold, relating to specimens on display or for sale in the museum. This year, on Saturday at 12:00, visit our gold miners camp, where Museum docents will demonstrate gold rush mining methods. See the tools, weapons and methods used by the 49ers to survive and find gold during the gold rush.

The show includes a silent auction of jewelry, rocks, and minerals. Geode cutting is back again by popular demand, and you will find many unique jewelry items handcrafted by local member artists, at the Mariposa Gem and Mineral Club booth. Local vendors will also be available with a variety of food items.

This year’s vendor information letter is available here.  The vendor registration form is a separate document available here.

For information call: 209-742-7625, and view our 2019 printable poster here.