Soft white talc - hand specimen from the Acme Mine, Alexander Hills, San Bernardino County, California

$ 7.50

The Western Talc Mine - Acme mine was the second largest talc mining operation in the Death Valley region. The southern Death Valley area talc deposits are some of the best examples in the U.S. of talc formed by contact metamorphism. Mining began there around 1910. There are at least 43 talc mines and prospects in the region. Only one mine is currently in production. Mines in the Death Valley National Monument ceased production in 1988.

This talc formed when a cherty dolomitic horizon at the bottom of the Crystal Spring Formation was intruded by gabbroic sills in the Mesoproterozoic, roughly one billion years ago. The sills were emplaced before the overlying limey sediments had consolidated and while they were saturated, perhaps by marine water from an overlying sea. Contact metamorphism produced the talc along the contact between the sill and the carbonate metasediments. Two gabbroic sills in the area gave U-Pb radiometric ages of 1087+  and 1069+3 million years.

Talc is the softest mineral, 1 on the Mohs scale.The Death Valley talc has been used mainly in the manufacture of ceramic wall tiles and as an extender in paints.

This talc is too soft to withstand student examination well. We recommend it as a specimen to be examined carefully.  This talc makes an excellent display specimen.

 

 

 

 

Ships in a Regional Priority Mail box and can be combined in that box with other purchases. Please request an invoice to avoid overpaying shipping, by clicking the "combine shipping" button in the cart.

Click > About Shipping < for shipping rates. Use back button to return to this page. 

Select a specimen: You can select a specimen by telling us what is in the photo with it, a blue or black and silver pen, a black mechanical pencil or one of those plus some number of coins, or you can let us make the selection.

Making multiple purchases? Click on the "combine shipping" button in the shopping cart. We'll send an invoice with the least expensive shipping. A link in that invoice will bring you back to checkout, no hassle.