Michigan!
A selection of minerals from northern Michigan, including a number of interesting datolites. In all but a few cases, I've tried to post specimens that are actually attributed to a particular mine or locality. Whether it is copper (or even more frequently, datolite) the information somehow tends to get lost... I suppose it's understandable, considering many specimens from the area are quite old, and the habits are not always clearly distinguishable from one location to another....(though I know many a Michigander who would disagree with that last statement...)
List
Grid
DST01 Copper
Kearsarge Mine, Houghton Co., Michigan, United States
14.0x 10.0x 4.8 cm
$1600
A great copper specimen from the Kearsarge Mine, at the far Northern tip of Michigan's Upper Peninsula. The Kearsarge Mine operated between 1897 and 1931, and again for a few years in the middle of the century; this piece likely dates to the earlier interval.
When it comes to Michigan copper, I personally look for 3 things: clear sharp crystals, good patina, and an attractive overall from. This self-standing piece checks all three boxes, with numerous crystals and crystal faces visible throughout, and the left branch being a cluster of large, elongated crystals with very clear form. The overall shape of the piece is quite sculptural as well, and the size and its visual balance make for a particularly nice display.
MCU01 Copper
Phoenix Mine, Keweenaw Co., Michigan, United States
4.7x 2.0x 1.3 cm
$485
A well crystalized copper specimen from the Phoenix Mine, located near the northernmost tip of Michigan's Upper Peninsula. This mine operated between 1849 and 1929. This piece consists of a cluster of fairly sharp, elongated crystals.
MCU02 Copper
Quincy Mine, Hancock, Houghton Co., Michigan, United States
7.2x 3.4x 2.6 cm
$395
A nice example of dendritic copper crystals, from the Quincy Mine in Michigan's Upper Peninsula.
MCU03 Copper
Central Mine, Keweenaw Co., Michigan, USA
5.1x 3.x 1.6 cm
$395
A cluster of sharp copper crystals from the Central Mine, operated between 1855 and 1898. As with most Michigan coppers, it's impossible to know whether it came from the dumps or the actual mine, but either way such sharp crystals are not nearly as abundant as the rounded, weathered stuff that has sat on the ground for decades.
MCU04 Copper
Keweenaw Peninsula, Michigan, United States
10.6x 8.8x 5.2 cm
$265
A nice example of a "copper skull." These formed when copper was deposited in a conglomerate by hydrothermal processes, then the enclosed stone eventually weathered or broke away. Kind of hard to focus the camera given the concave nature of the piece, and many small jutting bits of copper.
MCU05 Copper
Keweenaw Peninsula, Michigan, United States
11.5x 3.8x 1.8 cm
$195
A nice example of an elongated "copper skull." These formed when copper was deposited around stones in a conglomerate by hydrothermal processes, then the enclosed stone eventually weathered or broke away.
MCU06 Copper
Keweenaw Peninsula, Michigan, United States
3.4x 3.2x 1.6 cm
$285
A group of copper crystals on a rock matrix, featuring a single, unusually sharp and distinct crystal.
MCU07 Datolite on Copper
Keweenaw Peninsula, Michigan, United States
4.1x 3.5x 2.7 cm
$695
This is one of my favorite pieces in the update-- a highly unusual combination of a MATRIX datolite with copper. Michigan's Upper Peninsula is primarily known for 3 species: copper, silver, and datolite. The first two frequently occur together, but apart from tiny metal inclusions, datolite is almost always found alone, as loose nodules.
This piece has a half-polished datolite nodule that is attached to a bit of matrix, which is composed of a mixture of copper and stone. There is also a copper crystal on the matrix next to the datolite. I've only ever seen a couple matrix examples of these UP datolites-- this piece is actually quite special.
MCU08 Datolite
Mesnard Mine, Hancock, Houghton Co., Michigan, United States
12.4x 8.9x 4.0 cm
$785
An unusually large (at least by the standards of what I'm used to seeing) datolite nodule from Michigan's Upper Peninsula.
MCU09 Datolite (Yellow!)
Keweenaw Point, Keweenaw Co., Michigan, United States
2.9x 2.4x 0.8 cm
$275
A nice example of a yellow datolite nodule with a polished face, from Keweenaw Point. This is the northeastern-most point of Michigan's Upper Peninsula, less than 50 miles from the border with Canada that cuts across Lake Superior.
Yellow is perhaps the rarest and most sought after color for Michigan datolites; this is a rather nice example.
MCU10 Datolite (Yellow!)
Keweenaw Point, Keweenaw Co., Michigan, United States
2.5x 2.0x 0.7 cm
$225
A nice example of a yellow datolite nodule with a polished face, from Keweenaw Point. This is the northeastern-most point of Michigan's Upper Peninsula, less than 50 miles from the border with Canada that cuts across Lake Superior.
Yellow is perhaps the rarest and most sought after color for Michigan datolites; this is a rather nice example.
MCU11 Datolite
Centennial Mine, Houghton Co., Michigan, United States
3.7x 2.8x 1.4 cm
$135
A pretty example of a dtolite nodule with a light green tinge, resulting from altered copper inclusions.
The centennial mine operated intermittently from from 1863 util 1966, this was likely collected from the dumps.
MCU12 Datolite
Keweenaw Point, Keweenaw Co., Michigan, United States
2.3x 1.7x 0.8 cm (larger half)
$295
A nice example of a complete yellow datolite nodule, split in half and both faces polished. This comes from Keweenaw Point. This is the northeastern-most point of Michigan's Upper Peninsula, less than 50 miles from the border with Canada that cuts across Lake Superior.
Yellow is perhaps the rarest and most sought after color for Michigan datolites; this is a rather nice example.
MCU13 Datolite (Yellow!)
Keweenaw Point, Keweenaw Co., Michigan, United States
3.5x 1.8x 0.9 cm (larger half)
$365
Two end cuts from a rare yellow datolite nodule from, from Keweenaw Point. This is the northeastern-most point of Michigan's Upper Peninsula, less than 50 miles from the border with Canada that cuts across Lake Superior.
The labels affixed to the backs of both pieces indicate "173a" and "173b." Yellow is perhaps the rarest and most sought after color for Michigan datolites; this is a rather nice example.
MCU14 Datolite (Yellow!)
Keweenaw Point, Keweenaw Co., Michigan, United States
2.6x 1.9x 1.2 cm
$185
A nice example of a complete yellow datolite nodule, split in half and both faces polished. This comes from Keweenaw Point. This is the northeastern-most point of Michigan's Upper Peninsula, less than 50 miles from the border with Canada that cuts across Lake Superior.
Yellow is perhaps the rarest and most sought after color for Michigan datolites; this is a rather nice example.
MCU15 Datolite (Yellow!)
Keweenaw Point, Keweenaw Co., Michigan, United States
2.0x 1.6x 0.6 cm (larger half)
$195
Two halves of a rare yellow datolite nodule from, from Keweenaw Point. This is the northeastern-most point of Michigan's Upper Peninsula, less than 50 miles from the border with Canada that cuts across Lake Superior.
The labels affixed to the backs of both pieces indicate "123a" and "123b." Yellow is perhaps the rarest and most sought after color for Michigan datolites; this is a rather nice example.
MCU16 Datolite (Yellow!)
Keweenaw Point, Keweenaw Co., Michigan, United States
3.5x 2.3x 0.8 cm
$175
A nice example of a polished yellow datolite nodule half This comes from Keweenaw Point. This is the northeastern-most point of Michigan's Upper Peninsula, less than 50 miles from the border with Canada that cuts across Lake Superior.
Yellow is perhaps the rarest and most sought after color for Michigan datolites; this is a rather nice example.
MCU17 Datolite (Yellow!)
Keweenaw Point, Keweenaw Co., Michigan, United States
2.4x 1.9x 0.5 cm
$185
A nice example of a polished yellow datolite nodule half This comes from Keweenaw Point. This is the northeastern-most point of Michigan's Upper Peninsula, less than 50 miles from the border with Canada that cuts across Lake Superior.
Yellow is perhaps the rarest and most sought after color for Michigan datolites; this is a rather nice example.
MCU18 Datolite
Drexel Mine, Delaware, Keweenaw Co., Michigan, United States
5.0x 4.1x 1.4 cm
$165
An unusual police diatomite nodule half, the outer rind is more datolite (not the usual rocky stuff) and the whole thing is translucent. When viewed up close, there are tiny reddish spots-I'm guessing it's copper. Unusual example.
MCU19 Datolite
Delaware Mine, Delaware, Keweenaw Co., Michigan, United States
3.4x 2.8x 0.9 cm
$95
A nicely veined daoloite nodule with bits of reddish coloration, from the Delaware Mine. This mine operated during the last 2 declared of the 19th century, though this was probably collected much later on the dumps.
MCU20 Datolite
Mesnard Mine (Quincy #8 Shaft) Quincy Mine, Hancock, Houghton Co., Michigan, United States
6.0x 4.4x 3.1 cm
$235
A nice half of a datolite nodule from the Mesnard Mine (apparently a section of the Quincy Mine). There is a sticker with a handwritten note on the bottom: "Bought Wayne (?) 1957"
MCU21 Datolite
Delaware Mine, Delaware, Keweenaw Co., Michigan, United States
4.7x 4.1x 1.1 cm
$125
A nice example of a polished datolite from the Delaware Mine.
MCU22 Datolite
Mesnard Mine (Quincy #8 Shaft) Quincy Mine, Hancock, Houghton Co., Michigan, United States
4.8x 3.5x 1.0 cm
$85
A polished section of a brick colored datolite nodule from the Mesnard section of the Quincy mine.
MCU24 Datolite
Keweenaw Peninsula, Michigan, United States
3.4x 3.1x 1.0 cm (Larger half)
$48
Two polished halves of a sliced datolite nodule from Michigan.
MFS24 Copper
Northwestern Mine, Keeweenaw Co., Michigan, USA
5.0x 3.7x 2.0 cm
$225
A decenly sized copper crystal from one of the more obscure Michigan copper mines. Please note that it can only be displayed from the front.
The Northwestern Mine was worked intermittently from 1846 to 1865. This piece was collected from one of the dumps that remain.
