Archive for May, 2009

Isle Royale Greenstone/Chlorastrolite (AKA Michigan Greenstone, Greenstone, Pumpellylite)

Tuesday, May 26th, 2009

Michigan’s State Gem, the Isle Royale GreenstoneGreenstone Pendant with Datoliteis unquestionably one of the rare minerals of earth. It can only be found on Isle Royale National Park and in Michigan’s Keweenaw Peninsula. Greenstone is a close relative of Epidote. Chlorastrolite (translated from Greek as green, star-like stone) is actually a form of Pumpellyite. “Chlorastrolite” was adopted as Michigan’s gem March 30, 1973.

Greenstone formed in amygdaloidal pockets of Keweenaw basalts. At one time Isle Royale and the Keweenaw formed one land mass. Isle Royale was spit off from the Keweenaw when the rift that formed Lake Superior split a giant gash in the earth.

Thanks to Benjamin Franklin, the Keweenaw Peninsula and Isle Royale are part of the United States. Franklin was a member of the commission that drew up the boundaries for the Treaty of Paris in 1773, ending the Revolutionary War. Ben Franklin had heard of the rich mineral deposits in the Keweenaw and Isle Royale so he drew the boundary line to the north of Isle Royale, giving this area to the United States instead of Canada.

The mineralization on Isle Royale is exactly the same as the Keweenaw. Native copper, Datolite, Prehnite, Thomsonite, Lake Superior Agates, Epidote, Greenstones, and the same basalts are seen in both locations.

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As the basalts cooled, gasses tried to escape to the surface, the bubbles becoming smaller and smaller as they rose and tried to escape from the basalt’s clutches. The basalt hardened and trapped these bubbles known as “vesicles”. Also the cooling created shrinking and cracking of the basalt. These cracks in the basalts allowed different minerals in solution to flow into the vesicles, where they eventually solidified.

Copper, silver, arsenates, and other metals also filled the cracks and vesicles, but were disseminated by rising, super heated water instead of flowing down from the surface. The vesicles that the copper and other metals filled were sometimes huge and other times just cracks or small bubbles.

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Greenstone with Datolite and Copper

Greenstone with Prehnite

Greenstone with Prehnite

Copper associated itself with other minerals including all the previously mentioned material. The variety of material, mixed in different ways, is what makes this rock hunting area so intriguing. It is wonderful to see copper running through Greenstone, Datolite, Prehnite, and Lake Superior agates. Pieces of Greenstone/copper are highly coveted by collectors and jewelry makers like myself. The few pieces I have are priceless. My wife has a ring made out of one of these copper/greenstone pieces, and I still have a couple specimen pieces. She sometimes wears the ring to art shows, so ask her if you see us.  To see an example of copper with datolite, take a look at my Copper Lightning Datolite.

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Greenstone with Thomsonite

Greenstone sometimes has Thomsonite inclusions, which make for a spectacular look. (Dark, chatoyant green and dark pink together) I’m waiting to find a Copper-Greenstone-Thomsonite some day. I have seen specimens of these at the Seaman Museum at Michigan Tech.

My next post will discuss finding and working with greenstones.


Victoria Stone (aka Iimori Stone)

Friday, May 8th, 2009

Victoria Stone is one of my favorite lapidary materials. It is actually a manmade jade created from natural materials by Dr. S. Iimori in the late 1960’s and early 1970’s. I have noticed that Iimori’s name is spelled several ways on assorted websites (ex. Imori), but the spelling I have comes from an article originally published in Lapidary Journal, so I assume it to be the correct spelling.  Articles from Lapidary Journal that I located show piles of natural materials (quartz, magnesite, feldspar, calcite, fluorspar, and others) stacked near Iimori’s laboratory in Tokyo.

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These materials were pulverized to dust and melted into molten masses. The secret beauty of Victoria Stone comes from the “crystallizers and crystal habit regulators” which Iimori added to the molten mix. The molten material resulting from the brewing was poured into molds and cooled under pressures, up to 2000 pounds, for several months.

When the Victoria Stone “boule” was released from its mold they had a crust on them.

I have seen these boules, which are a cylindrical shape with one flattened end and weight perhaps 3-4 pounds. My friends have told me that when working this material you had to remove the crust carefully and let the boule rest for a few weeks. They say that the boules would actually make cracking noises when the crust was removed. Expansion inside the boule caused these noises. The older the boule, the less cracking could be heard. They would cut a couple slabs off each end of the boule; leave is set for a couple weeks, and then cut two more slices off each end, etc.

Victoria Stone boules were sold at the Tucson Gem Shows in the 70’s. Also cabochons were available to purchase at the shows. I wish I had invested all my money in this stuff back then, as it is unbelievably expensive today, and virtually impossible to find. I have purchased entire rock collections just to get a small quantity of Victoria Stone. We are one of the few sites on the Internet to offer Victoria Stone Jewelry.

Victoria Stone is not considered a simulant, although it chemically resembles Nephrite Jade. Iimori actually manufactured an artificial jade that he called “meta Jade”. I still have some of this material and it is hard to tell the difference between it and natural Imperial Jade. The main difference between natural jade and Victoria Stone is when Victoria Stone re-crystallized from its molten state; it formed beautiful feather-like chatoyant crystal features. p1100285 I see similar crystallization in Pectolite (Larimar), Thomsonite, Isle Royale Greenstone, and Prehnite.

I call Victoria Stone a created natural stone because it was actually manufactured from natural rocks and minerals. The stone was originally produced in four shades or green, two of yellow, four of blue (My favorite baby blue), purple, black, white, red, grey, and brown. I have some wine colored Victoria Stone also and I recall there was an orange color also, if my brain is working right. I always have thought that orange and yellow were ugly colors. I have posted two photos of dark green Victoria Stone so you can see how the crystallization varies from stone to stone.

The first version of the Victoria Stone story is that Dr. Iimori died in the late 70’s or early 80’s and never told anyone how he produced Victoria Stone. Kenzo Kato, Iimori’s son, ran Iimori Laboratory Ltd., but was never informed of the secret to making Victoria Stone. I could never imagine not writing down somewhere how you did something as wonderful as making Victoria Stone, but this is what is said to have happened.

The alternate version of the aforementioned story that I have recently received from a trusted expert I know is that Dr. Iimori did in fact pass the formula to his son, Kenzo Kato. KATO did make a batch or a few batches of Victoria Stone which was sold on the market.  There was a problem with the Victoria Stones stability from Kato’s batches.  The batches were not stable enough for lapidary work.  Apparently the problem was in the cooling, pressure, or some other factor which was not passed on to Kato.  Shortly thereafter Kato went out of the Victoria Stone business.  This second version makes far more sense than the first story which is generally thought to be the definitive truth.  I believe that the story that Kato did know the formula is more creditable then the story that is generally thought to be the truth.

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My logical brain tells me that the aforementioned “crystallizers and crystal habit regulators” must have vanished in the manufacturing process or someone would have discovered the secret formula by now. Maybe someone knows something about this and will post back to me.

I cut Victoria Stone on my Genie as I would jade, except it polishes easier. Also Victoria Stone is quite resistant to edge chipping, but I still do not use a new 90 grit wheel on it. You also have to watch for natural holes in this material, and work around these small imperfections. You do not have to burnish Victoria Stone like you do jade to get a good polish. Victoria Stone produces a superior polish without heat. I would not recommend heating Victoria Stone up too much while polishing it lest you accidentally crack it. I have not personally cracked a stone, but have been told that this is a possibility.

Check out all our Victoria Stone Jewelry now. I expect that this beautiful stone jewelry will continue to increase in value as time goes on.

Roadrunner

Saturday, May 2nd, 2009

Snob Blog fans seem to like the unusual rocks I often make into jewelry . Here is a way cool Lake Superior Agate that I call “The Roadrunner”. Do you see the bird?   roadrunner1

The agate is a somewhat unusual color for a fortification agate and when I cut it, I was surprised by this great picture in it.

Sorry this was sold to Beth (the same Beth that owns the fantastic Isle Royale Greenstone that I previously Blogged about).  Take a look at my rhyolite Owl which is very unique, or The Parrot.  I have wire wrapped other Lake Superior agates into slides or pendants.  You also might enjoy the Crazy Lace agates pendants/slides.

If you are looking for a particular animal in a rock, you can E-mail me and I’ll keep an eye out for it. You will have to be patient as these pictures do not appear commonly. No guarantee on these requests!


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