Monthly Archives: September 2009

Bonnie’s Great Datolite

My wife Bonnie has been tagging along half-heartedly with me to Keweenaw Week for several years. She likes wearing my jewelry, but just never has found anything that got her really excited and proud. It always seemed like a lot of rock to look through, with most of it turning out to be nothing good. Those copper tailing piles are really big, and looking for the “good stuff” is a lot like looking for a needle in a haystack. And I hate her dragging non-jewelry grade stuff home and mixing it up in my barn with all my real treasures. (That barn is a whole other story. One that may never be told.)

Datolite is an elusive gemstone. We went to a mine that we’ve been to many times, hoping to find some good datolite. Of course for Bonnie this would be her first datolite, and she really had some low expectations. She’s spent hours digging holes that never gave up anything to take home. We have friends who seem to be able to just smell them and go right to them, and bring home a great story to brag about. Bonnie just wanted to find ONE. We chose to dig under some trees, figuring whatever was there hadn’t been seen in a long time. As the dig progressed Bonnie got dirtier and dirtier. That was the main thing I noticed. She made a pretty big hole, and pulled out a large chunk of rock that had two small (4-5mm) rounded white spots sticking out of one side. Now that’s the magic formula: rounded and white, so Bonnie put it in her bucket. It did register on the metal detector, so that was good too. But really, it didn’t look like much (those two small white spots are way too small for me to make jewelry with, that’s how I judge rocks).

Bonnie found one other datolite, not huge, but big enough to make jewelry from, so she was pleased with that. I got some cutting material, rock with copper running through it that should turn out pretty. We went home not too excited and I took a nap. Bonnie went to a faucet outside and began to scrub away some dirt from her rock with “twin towers” as she referred to them. The more she scrubbed, the more excited she became. A strip of white datolite began to show up on the bottom, other white rounded areas and some small copper points were poking out.p8120186

She continued to scrub off mud, finding more white nodules and got really excited. I wanted to see what the copper would really look like, so I gave it a quick acid bath. See for yourself. Bonnie’s “boring” datolite find, her very first, turned out to be a beauty that any rockhound would be ecstatic to find! This is part of the charm that keeps rockhounds coming back to the Keweenaw year after year. I expect she’ll be more excited about our rockhunts in the future. Copper and datolite nodules combined in one terrific stone clump. What could be better?

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Mohawkite

Originally named after the primary source at the Mohawk Mines (copper mines) in Mohawk, Michigan, Mohawkite is a rock that closely resembles fine gold in quartz from California.

Algodonite and domeykite are the two principal arsenides found in the Keewenaw. These two minerals when mixed with arsenian copper form Mohawkite. Mohawkite is one of them many historical names for this mixture. The Mohawk #2 as well as mines at Ahmeek were the primary source for this rock. A little know factoid is that over 100 metric tons of Mohawite were removed from the Mohawk mine between 1900 and 1901. The Mohawkite was massive in nature. p9130106

I have hunted Mohawkite on organized trips in the Keweenaw. I believe the Mohawk spoil piles are private property so make sure permission is gained before going on these piles. Mohawkite is elusive and requires some luck and a good metal detector to find.

I always treat Mohawkite with respect when working with it, always using gloves and a mask when grinding and polishing. I also change the water on the Genie and any saws I use after finishing with Mohawkite.

After the Mohawkite cabochon is polished, it is fairly docile (unless you plan to eat it!). I have been experimenting with coating the cabochon with industrial epoxy. This seals the metals against tarnish, but having said this, some people like the tarnished-natural look and prefer a natural, polished stone.

Mohawkite is an unusual and obscure jewelry material, and one of those special rocks to be found only in my favorite rock hunting location, the Keweenaw Peninsula.

I sell Mohawkite jewelry both on this website and at our art shows.

A Most Wonderful Greenstone Hunt

The location of this hunt will remain a secret other then to tell you it took place somewhere in the Keweenaw Peninsula. This took place in September 2009.
Sometimes I think we rockhounds are a little crazy to go out and bang on rocks in the hot sun and call it “fun”. I think this is what convicts in chain gangs used to do. I bet it wasn’t fun for them! Other times we are out in a downpour because this is the best time to spot the type of rock we look for.
Let me tell you about one of those trips to an old rock pile in the U.P. when it was pouring rain. Bonnie and I donned our heaviest rain gear and waterproof boots and headed to one of the old mine dumps where we had previously enjoyed some success finding Isle Royale Greenstone. Immediately we found greenstones literally “washing out” of the banks in one small area on the pile. This is when you suffer bouts of greed, amazement, and wonder.
We harvested these stones as well as finding numerous other rocks full of Greenstone that we will remove later at home by cutting or breaking the matrix. Greenstones, when found, are generally small, ugly, dark green nodules. Often I see a glint of chatoyancy in the nodule, or the nodule may be broken and you can see the pattern where the break is.
Many of the greenstones we were finding that day were over one inch and we could see good chatoyancy in the nodule. This is remarkable size considering the average greenstone is maybe half the size of a pea. Over the course of four or five hours we picked up a gallon size ice cream bucket of loose nodules and larger nodules in matrix, and another five gallon bucket of greenstone bearing basalt. Greenstones are very rare and are found nowhere else on earth except Isle Royale and in the Keweenaw. Picking up this many in one day is remarkable. In one day Bonnie and I found more greenstone than the total amount we have picked up all the previous years we have been hunting.
I expect we will never have another greenstone hunt like this. It amounted to being at the right place, in the right location, at the right time. Few hunts work out this good. Dealing with the elements and not caring; finding valuable gemstones like they were common quartz; collecting not only treasures but memories. How great this was. I wish you could have been there.
Some of these new stones will be for sale on this website in the near future.