This quarry dig is my personal favorite out of the two offered. Although the dolostone rock is extremely hard to break, fluorite and other highly collectable minerals are very abundant in this quarry. I would say it would be difficult to not find any fluorite. Sometimes it is so incredibly clear, that it can be hard to spot. Your eyes have to get used to searching for it, but once they do you will spot them all over the place.There are definitely enough to go around. This is an amazing trip I highly recommend to anyone in the Northeast who wants to find crystals.

Amazing fluorites found by the writer’s collecting partner Alexander Kim at previous Walworth open houses (Check him out on Instagram: @dirty_minerals).

Many other beautiful minerals are found at this quarry, the most notable being gorgeous golden sphalerites. Sometimes there will be droplets of tar like petroleum coating specimens. The petroleum can be removed with a organic solvent, but I think sometimes it really is aesthetically complimentary.

Two specimens found by the author: 1) A floater golden sphalerite crystal that was rolling around freely in a pocket with a few others that were attached to the walls. 2) A peculiar fluorite with an elongated hair like pyrite inclusion, complimented by a big shiny droplet of petroleum coating the dolostone.

Geology and Collecting: The Walworth Quarry works a stromatolite bearing Silurian dolostone. The mineralization occurs in a layer close to the surface of the bedrock in the high bench of the quarry. Like with the formation of Herkimer diamonds, the stromatolites provided space and protection for crystals to form in vugs.

The mineralogy of the locality is fairly simple with the only collectible minerals present in abundance being fluorite, dolomite, calcite, sphalerite, celestine, and gypsum var. selenite.

Before you Visit: The quarry does not have an official page for the open house, but usually it takes place on the second weekend of October. Arrive at the quarry early- 6:45 AM to register for the dig. Hard Hat and protective gear required for this location. Check local Northeast mineral club pages for more info.

Show up to the quarry to register for the dig at 6:45AM. Once registered, the rules will be explained and you will be lead to the site. The dig ends at noon. This rock works similarly to the dolostone to the east in which Herkimer diamonds are mined, meaning it is extremely hard. Bring a crack hammer, chisels, wedges, and a sledgehammer. Use flat chisels or wedges to work the cracks in rocks. Power tools are welcome at this quarry.

The best technique for splitting large boulders is feathering and wedging using a hammer drill to drill holes for wedges. A gas rock saw is also an extremely useful tool for extracting difficult specimens by slicing them out of the rock.

PPE is required on this dig. Bring a hard hat, steel toed boots, safety goggles, and gloves. The former three are a requirement. Remember also to bring plenty of water as well as snacks. There are restrooms on site but it is far away, near the entrance.

Special Thanks to The Dolomite Group for allowing the special privilege of mineral collecting in their quarries.

Sources:

https://www.mindat.org/loc-18146.html

http://fredmhaynes.com/2016/10/14/walworth-quarry-open-house/

The post Collect World Class Fluorite at the Walworth Quarry Open House in New York appeared first on Where to Find Rocks.

By Jeremy Zolan

Difficulty Level: Easy to Moderate

Supplies Needed:
Safety Goggles
Water
Sunscreen
Insect Repellant
Crack Hammer
Chisel
Shovel
Wrapping Paper for Specimens
Bucket
Sledgehammer (optional)
Prybar (optional)
Metal Detector (optional)

Description:

The Keweenaw Peninsula of Michigan has been nationally famous for over 100 years for its history of highly productive copper mining. The local basalt is criss-crossed with many thick veins of native copper that made up the main ore of many of the mines. Solid natural masses of copper weighing hundreds of pounds were found with relative frequency at the mines. Though these pieces certainly were the most valuable ore, the best specimens from the area are clusters of well formed copper crystals. Other metallic minerals can be found with the native copper such as silver, domeykite, mohawkite, and chalcocite. Many other interesting minerals like datolite, analcime, prehnite, agate, and thomsonite are also abundant in the Keweenaw Peninsula. While all the mines of the region are closed to copper production, many are maintained as museums and fee dig sites. There are also many abandoned mines in the area that can provide good digging in the dumps but be sure to acquire permission from landowners before visiting any location on private land.

Localities:

Central Mine:
US 41
Central, MI 49950

Photo by Dave Maietta

Map:

The large tailings piles of the Central Mine are visible from US 41 in Central, Michigan. Many collectors have had good luck recently working this location. Occasionally, contractors remove large quantities of tailings for construction purposes and this exposes fresh material. In addition to the standard copper specimens, copper included calcite and prehnite can be found here. Silver has also been found with copper here but it is rare. A metal detector is very helpful for sorting trough dump piles like those found at the Central Mine.

Caption: Calcite with copper inclusions. Central Mine, Central, MI 4.9 cm x 4.6 cm x 4 cm Ex. Rukin Jelks Rob Lavinsky Photo

Caption: Unusually large copper crystal. Central Mine, Central, MI. George Vaux collection at Bryn Mawr College. Scale bar is 1” long with rule at 1cm. Rock Currier Photo.

Caledonia Mine:
Website: http://www.caledoniamine.com/
906-370-1131
202 Ontonagon St,
Ontonagon
Michigan 49953

The Caledonia Mine is a fee dig site that requires an advance reservation. When digging at this site, collectors are given a large pile of stockpiled copper ore and tools to go through it. Weekly collecting events on Thursdays and Saturdays are also held from the first Thursday in June to the last Saturday in August on the ore pile. Advance reservations are needed for these too. The workings of the Caledonia Mine are impressively preserved and tours are offered too. The mine tours aren’t necessarily just geared for casual guests. Many kinds of tours are offered, some with a very in depth historical or scientific focus. It is best to check the museum calendar to see if any events are happening during the time of your visit.

Caption: Representative specimen of native copper from the Caledonia Mine’s recent workings. 5.6cm wide. Rob Lavinsky Photo

A.E. Seaman Mineral Museum
Website: http://www.museum.mtu.edu/
Michigan Technological University
1404 E. Sharon Avenue
Houghton, Michigan 49931-1295
E-mail: tjb@mtu.edu
Telephone: (906) 487-2572

Michigan Tech’s A.E. Seaman Mineral museum is among the finest mineralogical museums in the world. Its laboratories are also critical in performing much of the cutting edge mineral research currently being performed. During the period of most intense copper mining in Michigan, many specimens of local minerals were donated to the museum. Their collection of Michigan minerals is the finest in the world and there is a strong local emphasis on their displays.

Check out our custom search and view all the minerals from Michigan for sale on eBay. Not only will you see lots of neat stuff for sale, you’ll also get an idea of what localities are producing in the region.

The post Collecting Copper in Michigan’s Copper Country appeared first on Where to Find Rocks.