mibeachrocks
starting to spend too much on rocks
Member since September 2013
Posts: 198
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Post by mibeachrocks on Sept 27, 2013 9:45:38 GMT -5
Just started a new batch the other day. I'm running 3lbs. of Leland Blue through a rotary tumbler. I ran them through a fine grit for 24 hours to round out a few of the rough ones. I'm interested to see how they turn out. There a a lot of voids (air bubble) and inconsistencies in the material. However, the colors are great (greens, blues, purples, turquoise).
Here is the before photo
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Post by Jugglerguy on Sept 27, 2013 14:58:59 GMT -5
I picked up some slag in Christmas, MI this summer. It doesn't look anything like yours though. Mine mostly looks exactly like obsidian, but some is very colorful. The colorful stuff seems more likely to have air bubbles.
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Post by Drummond Island Rocks on Sept 27, 2013 15:21:00 GMT -5
Should be a nice tumble. keep us posted From what I understand the stuff labeled leland blue is more specific than the average slag glass. This website has some decent info on local Michigan stuff and includes some history on leland blue. ontherockstc.com/pages/michigan-stone-infoI picked up a 7 pound chunk off ebay and have been slabbing and cabbing it. It does take a great shine in the tumbler just be careful to clean out the pits between stages.  Chuck |
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riverrock
fully equipped rock polisher
Member since April 2010
Posts: 1,395
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Post by riverrock on Sept 28, 2013 18:23:42 GMT -5
Looking forward to see them done.
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mibeachrocks
starting to spend too much on rocks
Member since September 2013
Posts: 198
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Post by mibeachrocks on Sept 30, 2013 7:37:26 GMT -5
Update... Here are some pics after 48 hours in a rotary tumbler with 600 grit. I made sure that I rinsed them very good after the previous stage. As you can see, leland "blue" can take on a bunch of different colors. They are currently in the polish stage. I hope that they will done tonight.   |
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mibeachrocks
starting to spend too much on rocks
Member since September 2013
Posts: 198
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Post by mibeachrocks on Sept 30, 2013 8:31:15 GMT -5
Jugglerguy, I also found some near Petoskey and Sutton's Bay, which was more like obsidian but with too many air pockets to tumble.
Chuck, thanks for the article. It is a great waste product to work with. If you decide to sell that cab, I'm sure you would get a pretty penny especially up north. It is amazing what a nice piece of leland blue or petoskey stone will fetch in a jewelry store up north.
What I forgot to point out in the last post is that the darker "stones" are not black (they show up grey in the first post because of the etching on the surface) but purple and translucent like very dark piece of glass. When finding them along the beach, it is very easy to tell them apart from basalt by holding them up to the sun. Also, they weigh less. The hard part about finding the turquoise and blue stones is that lake Michigan beaches also contain blue chert which chert that is stained blue on the exterior only. One simple way to tell them apart is Leland blue usually contains white to tanish specks (impurities). You can also see in the photos that several also still contain iron.
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mibeachrocks
starting to spend too much on rocks
Member since September 2013
Posts: 198
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Post by mibeachrocks on Oct 1, 2013 14:06:53 GMT -5
Update. I ran them through the polish stage for 72 hours. Depending on how the look tonight, I will run them through a burnish stage. I pulled one out to check its progress. I am happy thus far. To give you guys/gals and idea of what the darker ones look like, here are two photos. One without background light and one with. The white specks are impurities in the slag that are contained throughout. They give the translucent pieces a 3 dimensional aspect.   |
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Post by pghram on Oct 1, 2013 15:04:54 GMT -5
Interesting material, looking good.
Rich
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mibeachrocks
starting to spend too much on rocks
Member since September 2013
Posts: 198
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Post by mibeachrocks on Oct 3, 2013 13:21:47 GMT -5
Update. Ran 72 hours in polish stage. As you can see, the results are mixed. As you could expect, the material is not homogenous throughout. Some of it is very porous and some of it is glass-like. As would be expected, the glasslike material took the nicest shine. I did have a few surprises at the end of the batch. I had a zeolite that snuck in along with two dark green basalt rocks and a piece of blue chert. This is a picture of the batch sorted by material type/color. The greyish/opaque material is to the left and did not come out that good. The purple is in the upper center and took a nice shine. Most of it is glasslike and is translucent. The green is to the right (also called Frankfort Green in other parts of the state) is hit or miss. Some took a nice shine and others were to porous. The true Leland Blue are in the lower right. Most of them came out really nice. No wonder this is why they use this kind for jewelry.  some of the nicer "stones"  A few grey pieces did come out nice mostly because of the banding.  This was a nice surprise. After polishing all of the stones, a few seem to have copper inclusions along with iron.  I should have a few more pics this week. One lesson that I learned is that next time (I should have enough for two more batches) is will seperate the material into different types. While most took a nice polish, some could have gone a little longer. |
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mibeachrocks
starting to spend too much on rocks
Member since September 2013
Posts: 198
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Post by mibeachrocks on Oct 17, 2013 9:08:37 GMT -5
Here is the last of the pictures. These are examples of purple slag from Leland. Starting from the left (all stones are dry), beach washed stone, after 24 hours in 200 grit silicon carbide, 48 hours in 600 grit and 72 hours in polish.  |
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riverrock
fully equipped rock polisher
Member since April 2010
Posts: 1,395
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Post by riverrock on Oct 17, 2013 14:22:17 GMT -5
A well done batch.
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Post by pghram on Oct 17, 2013 21:13:01 GMT -5
Looks nice. If I am reading right, you are using a rotary. If so, more time in polish, like a couple of weeks, might make them even more shiny.
Rich
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mibeachrocks
starting to spend too much on rocks
Member since September 2013
Posts: 198
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Post by mibeachrocks on Oct 18, 2013 8:38:26 GMT -5
Rich, you are correct. I am still new to rock tumbling, so I am happy to take any and all advice. I have enough material for at least two more tumbles. Since I've never heard of anyone tumbling the material (I'm sure they have but I have yet to find one), this first attempt was more of an experiment. While it is all slag, there is a lot of variety in it. I think I know enough from the first attempt to know how to group the materials for the next attempt. My other concern, especially for the smaller pieces that are more valuable, was how quickly it would shrink. I will be sure to let you know how the next batch comes out. I have some quartz in right now so I'll probably run some in a month or two.
jason
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