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Dwarves' Earth Treasures Online Museum:
Clark Datolites found by JA
Clark Swamp Adit, Copper Harbor, Keweenaw CO., Michigan
Field-collecting Status:  Forestry Management and licensed for lumbering.
OK to Collect but at one's own risk.

    It's funny how the Clark Mine is better known for its datolites instead of copper. The Clark Mine is one of those early mines to be opened (around 1840s to 1850s), but did not produce a profitable supply of copper. With an exception of illegal attempt at bulldozing (he was caught), it's one of very few mines that I know of that had not been bulldozed or hauled away for rock crushing. Many datolites from Clark Mine are white and some consist of many datolite nodules squeezed together while some orange datolites are occasionally found at the dumps that came from one of the partially hidden adits to the north. I didn't know that some orange datolites had been found until I started digging there on August 2010 and by chance hit on a nest of datolites (about 35 datolites in one spot) including a block of "mudrock" with several datolites still attached to it. As of August 2012, I did not seem to find any virgin areas to dig for datolites even I found one in August 2015. I'm still finding some datolites from time to time but it's hard to find something when local rockhounders keep messing the piles up.  It's possible to extract some datolites out of a nearby outcrop but the basalt matrix is generally hard to break apart.

You can click on the pictures to see larger pictures.
pic pic
Where is Clark Swamp Adit?!
Old diggings

My first datolites found at
from Clark Mine, August 2008
Bright orange color,
August 2010
I'm amazed to find this one
even the mine dump was
totally messed up by the diggers.
August 2015
datolite datolite datolite
August 2011 In matrix, August 2012 No colors, August 2010
datolite datolite datolite
August 2012 August 2012 August 2010
datolite datolite
Reddish-orange,  August 2012 yellowish-orange, August 2011 Rare reddish color.
(obtained from someone else)
datolite datolite datolite
Bright orange to red datolites in matrix,
August 2010
August 2010 August 2011
datolite datolite
August 2013
(nearby outcrop)
August 2013
(nearby outcrop)
Largest datolite I have ever found
and it's orange! YAY!!
(nearby outcrop),  August 2013

Many dirty orange datolites in this mudrock found by Jeffrey A. August 2010.
A great specimen to show how datolites are formed in the mud filling in the cracks within boron rich basalt beds.
It was said that the trees would root quickly into the datolite rich mudrocks, so the prospectors
would look for any trees that had been uprooted and check what's below.
That may explain the myth of digging for datolites under the trees at the piles.