Prehnite and Other Pebbles from the Keweenaw

I discovered quite a few samples of Prehnite mixes that I found in the Keweenaw. All of these came from my cabochon collection, so I decided, this month, to follow up my blog on Patricianite in October, by showing you a small sample of what can be found on the beaches and in the hills of the Michigan’s Keweenaw Peninsula. Out of all the rocks and minerals in the Keweenaw, these little Prehnites are one of the most common treasures. On the beaches they wash in as pastel pebbles standing out against a rocky background of reds and browns. In the forest roads, quite often, Prehite’s have a white crust ( a little secret Rockhounding tip) with no clue as to what is hidden under the crust. I just pick them, take them home, and grind off a bit of crust. Maybe there’s treasure under the crust, maybe not.

I do not own expensive scientific instruments like a Scanning Electron Microscope (SEM), so I do not have the capability of analyzing every Prehnite mix I find, but I can tell you there is no limit to Nature’s recipes in regard to these beautiful pastel Treasures.

You may know that in the past, because of their resemblance to the Zeolite Thomsonite, this variegated, sometimes eyed Prehnites, were thought to be Thomsonite. Research done at Michigan Tech revealed that these “U.P. Thomsonites” were substantially Prehnite Mixtures. The old time rockhounds still refer to these as U.P. Thomsonite.

Sometimes you feel like an eye, sometimes you don’t. I suspect the suspect on the left may include Datolite.

Lovely pastel greens and pinks (color caused by micro-copper inclusions) dominate U.P. Thomsonite.

The patterns are so varied it's amazing.

The patterns are so varied–collecting is fun and addicting!.

Notice the brachiation (various spellings) in the right hand stone.

Jewelry grade

Can you make jewelry from Keweenaw Prehnite?

Botrioidal Keweenaw Prehnite rough

A thin Patricianite seam. Yes, that copper sheet is embedded in it.

Patricianite Rough (Non-seam material)

Here’s a little trivia you may not know about the mineral Prehnite: The first modern mineral to be named for a person was…..PREHNITE. Abraham Gottlob Werner of the Freiberg Mining Academy, was a popular teacher, but is also credited for delaying the advance of Geology by insisting upon wrong concepts on the origin of rocks and minerals. He WAS successful in classifying minerals. Werner named the mineral Prehnite after Col. von Prehn after von Prehn brought the mineral to Europe from the Cape of Good Hope (1783), where he found it.

I love rock trivia. I found this knowledge in a 45 year old book I have. Let’s take a look at some of the variations of Keweenaw Prehnite. Where possible I will show the cabochon before it became jewelry.

This Patricianite sports loads of Copper. I think it would look good as jewelry.

Why, yes indeed it did look good as jewelry.

Prehnite is a Copper Associate Mineral in Copper Country. Much of the Prehnite contains copper dust that changes green Prehnite to pink Prehnite. Other inclusions in Prehnite also produce a plethora of colors. Zeolites sometimes mix with Prehnite (A calcium Aluminum Silicate) in the Keweenaw and produce feathery eyes and patterns. Copper and Chlorite included Prehnite is sometimes referred to as “Patricianite” by copper country locals.

Pastel Patricianite with small Copper Inclusions. This was a massive chunk before slabbing.

Another one that made great jewelry.

Pastel Prehnites roll up on the beaches all along the west side of the Keweenaw Peninsula. While looking for agates, beachcombers may see a bright pink stone shimmering among other dull stones. Pick it up, it might be a coppery beauty. These nuggets can have pink and green together, sometimes even purple tones. I have found Prehnite in piles of materials cleared from road construction not far from Calumet. Prehnites are also gleaned from rock spoil piles at some mines. I have a secret hole that I also occasionally excavate for Prehnites. The best Prehnite has always been associated with Austraiia, but gemmy pastel green Keweenaw Prehnite with Copper inclusions, in my opinion, gives the Aussie stuff a run for the money.

Prehnite with Copper. This is the high quality stuff often found in slim seams.

Prehnite with very little Copper. This is the high quality stuff often found in slim seams.

Prehnite is sometimes referred to as U.P. Thomsonite because its’ appearance often mimics Thomsonite, with eyes, radiating sprays, and variegated inclusions. Some Prehnite is difficult to tell from Thomsonite, or other Zeolites, and for many years Prehnite was thought to be a Zeolite. It was determined by Analysis by Michigan Tech geologists that Prehnite is not related to the Zeolites, but can be associated with Zeolites. Prehnite is a Calcium Alumosilicate. More confusing is when Zeoiles mix with Prehnite and make the Prehnite look exactly like Thomsonite. Thomsonte is almost an exclusive American Gemstone (more trivia for you guys), Prehnite is much more scattered and can be found in numerous locales around the world.

Loads of Copper in this Prehnite. Mine seam material.

Loads of Copper runs through this Prehnite, a mine seam material.

A beautiful oddball dug from a hole somewhere in the Keweenaw Peninsula. Prehnite, assorted Zeolite and other stuff. A beautiful mix, don’t you think?

The Apple Green Prehnite from the Keweenaw can be found as small round Crystals, but in most cases as slim veins in the Amydaloidal basalt. I have found much of the Prehnite in my collection in veins that are less that one inch. The Prehnite seems to form within a void from the outside in, meeting in the middle of the void. After extracting the Prenite bearing host basalt, I usually split the Prehnite where it meets in the middle. I can then use both sides to make beautify cabochons and jewelry. I like when the Prehnite sometimes does not completely close off in the middle of the seam, leaving a void where Prehnite Crystals form in a drusy. Remember it is often possible to find copper within the U.P. Prehnite. Copper can be found included in most every Keweenaw mineral.

The Seaman Mineral Museum, in Houghton, Michigan, has some wonderful, large Prehnite crystals found by miners over the years. Knowing that a Mine Captain or Superintendant or other mine management person was a mineral collector, the miners could score some points by turning these specimens over to them. Some of the finest specimens at the Seaman Museum were from these historic collections donated to the museum by heirs or willed by the owners of the collections.. Two of the most prolific collectors were J.T. Reeder, who clerked at several different mines, and L.L. Hubbard who discovered the Champion Mine and served as general manager of the mine. It is interesting to read and learn about these early collectors. Hubbard willed some of his collection to the University of Michigan, and recently the U of M has given many Copper Country specimens, from historic collections, to the Seaman Museum.

Many rockhounds overlook Prehnite or Patricianite while rock collecting in the Keweenaw. it’s one of my favorites and I never miss a chance to pick up nice pieces. So what do you think? Does Prehnite/Patricianite make good jewelry? You are invited to visit my jewelry pages to see the variety created from Keweenaw Treasures, especially Prehnite .

Datolite, Copper and Quartz Pendant

I’ve decided to write some mini-blogs to keep you up on activities at Snob Appeal Jewelry. I will be keeping you up to date about waht takes place in my shop, on my workbench, and in Bonnie’s Bead Room.

Last week I cut a beautiful Cabochon from a piece of Datolite I bought from a friend in the Keweenaw earlier in August. I don’t usually use White Datolite as there are many more colors of Datolite that are far more coveted. White is common and was found in most all the Copper Mines in the Keweenaw. It is impossible to determine what mine White Datolite came from. Most colored Datolite can be identified with what mine it may have come from.

White Datolite generally has very little “character”, but sometimes, as in the case of this piece, it has character to the max. Copper always adds character to Datolite no matter what color. White Datolite with Copper inclusions and Quartz is especially fine.

I cut this piece into a large bold teardrop shape (30 X 40 mm). Since the Datolite is so showy, the wrap needed to be simple and elegant. I love using Pink Gold whenever I have loads of native copper in a stone. Pink gold’s coloration matches Copper well, but you do not have the Oxidation with Pink Gold like you do with Copper. I combined Pink Gold and Argentiun Sterling for this piece.

Whenever you wrap a calibrated Cabochon, you have to be as identical on the right and left side as possible. Any variation from side to side are readily noticed, and this is why many wire wrappers avoid calibrated cabochons. This pendant could be worn by a man or woman.

I hope you enjoy these small blogs.

Datolite & Copper

My wife, Bonnie, was randomly searching through, buckets, boxes, bins and drawers the other day. She does this occasionally in my shop and storage areas; or she might just decide a dirty bunch of rocks needs to be cleaned.

This cleaning activity produced a beautiful little Datolite/Copper slab that looks like it may have been from the Delaware Mine pile (back before it was hauled away for road fill). This little beauty proved, beyond a doubt, that Copper and Datolite in the Keweenaw are indeed associated. This one was definitely a happy combination.

I cut and wrapped this very simply. A stone this flashy doesn’t need much. Doesn’t the Pink Gold look good on this one?

A Loony Greenstone

In a large hoard of small tumbled Greenstones from Isle Royale, I noticed an odd shaped one. Closer examination revealed it looked exactly like a Loon. I had an immediate inspiration to combine this particular Greenstone with another gemstone of a unique pendant.

A couple weeks later my wife, who always seems to be trying to improve the neatness of my barn and shop, located a great piece of clear Quartz with Rutile ribbons included. The stone remind me of a reed bed in some Northern Lake where a Loon might nest.

The pendant turned out just as I envisioned it. At 2 1/4″ tall and 1 1/4″ wide, it makes an impressive pendant. I made it from Gold wire and Pink Gold wire. I’m going to test-wear it a while and sell it on line.

Specular Hematite at the Beacon Mine in Champion Michigan

It can be a bit confusing when I say that we picked up some Speccular Hematite at the Champion mine in Champion, Michigan. The old abandoned mine dump in Champion is actually the Beacon Mine. The Champion Mine is a copper mine that is located near Painesdale in the Keweenaw Peninsula. This month I’m strictly speaking about the Iron mine in Champion.

Bonnie is picking up small pieces of Specular Hematite for kids grab bags.

A great place to stop on the way back from rock hunting or participating in Art Shows in the Keweenaw Peninsula is the old Beacon Mine in Champion, Michigan. On a sunny day this place looks like a fairy land. The Iron Mica- rich Specular Hematite (Specularite) exudes a silvery sheen. Driving back to the old piles on a sumny day you notice the two-track road is covered with silvery, shiny dust. When you leave this place your clothes and vehicle will sparkle. I have found, many times, my tire sidewalls still sparking after several days back home. Even it you don’t pick up any Specularite (Yeah right!) you should still go take a look at the stunningly shiny, silvery piles and roads. I know one lady that puts the road sand in small vials and gives them away as “fairy dust”.

Specularite can vary in coloration and makeup.

Google earth and this website will direct you to the mine dump: http://www.mindat.org/loc-3839.html. Turn at the blinker on US-41 in Champion, go up the hill and keep going until you see a little road that looks like a driveway AT/AAJ I think is the street. Anyway look for the “AT” the street starts with. Take that street and it will turn into a mica-covered single track road that goes back to the piles.

The waste piles produce a never-ending supply of rock. Specular Hematite is mostly a garden rock; iron that is slow to rust and adds a little shimmery touch to any garden, especially on a sunny day. This stuff is iron-rich and heavy.

Quartz is a fairly common inclusion at the Beacon Hill Mine. Many minerals have been found associated with the Specular Hematite.

You can cut and make jewelry from Specularite, but this rock makes a black, muddy mess of your saws and equipment. The black mud will get all over you and your shop. Specularite should be coated and stabilized when in jewelry because of its crumbly nature, and its’ habit of shedding Mica. I speak from experience here, when I tell you it is not worth the effort of making jewelry from this material.

You could be lucky to find drill cores at the mine in Champion.

Bring a strong back, especially if you find the perfect specimen a ways from your vehicle. If we have some room in our truck, we always stop at Champion and throw in some ballast. The piles can be unstable, so I recommend steel-toed boots and good leather gloves. Boots have saved my toes a couple times. Don’t blame me for smashed fingers. Also a sturdy shovel or pry bar can help if you go for the big ones. A strong wife or big, dumb, buddy can also be of assistance. “Hey, I’ll bet you can’t carry that piece back to the truck”. This will always get the macho guys motivated. I admit, in my younger days, I fell for this line a few times.

Siderite: An Iron Carbonate

Careful hunting may produce wonderful specimens of Specularite, Magnetite, Tourmaline (Black) in Quartz, Pyrite, Mica, Masonite, and on rare occasions Garnets. I have also found Siderite, and the list of minerals you might find is substantial (on the Mindat website). If you are lucky, you may find Specularite drill cores. I love the Golden Mica and Specularite combinations careful rockhounding might produce.

I see piles of Champion rock being sold in Quartzsite and Tucson for $1.00 a pound (“If you take a hundred pounds”). So you can buy this stuff at the shows or go get some yourself for much less. (I’m not counting your travel costs, that’s up to you!)

Pictures don’t do justice at this mine dump. You have to see the magic with your own eyes, especially if it is a sunny day, when it looks like fairy dust everywhere! Have fun and don’t hurt yourselves. I accept no liability for greed and/or stupidity at this location.

Datolite: One of the Keweenaw’s Colorful Mineral Treasures

I tried to do justice to a customer’s Yellow Keweenaw Point Datolite. earring and bracelet set.

You already know that Datolite is my favorite Calcium-Borosililicate. I just love the way that flows off the tougue, and it sort of makes you look smart when you say it. Datolite commonly occurs in the the Keweenaw in the Copper deposit host rocks in veins and vesicles. We also find Datolite in mine waste piles, often in the form of round, Califlower-looking crystals that have popped out of the host rocks left from mining Copper. If you find Datolite in the Keweenaw, you can be assured there is copper nearby..

Quincy Yellow

Franklin or Mesnard (?)

White Datolite can be from anywhere. This one containing classic Datolite Crystals.

The most common color of Datolite is white, and can be found in all the copper deposits in the Keweenaw. Pink is the second most common color. A close microscopic study of pink Datolite will reveal the pink hue is the result of micro copper within the stone. the darker the pink, the more copper in the Datolite.

Copper is the star in these three I’ve been saving for a personal piece of jewelry. From right clockwise: Keweenaw point Yellow Datolite, Copper Replacement Agate (Kearsarge Lode), Dark Chlorastrolite with Copper.

Centennial Blue (#2 Shaft)

Copper “Lightning” in Centennial Blue

Colors in Datolite run the entire color palette. Impossibly rare is the Canary Yellow from the Keweenaw Point. Unlike most Datolite in the Keweenaw this yellow Datolite gets its’ color from manganese and not Copper. This Point deposit is primarily under water, but has been covered with green algae for quite a few years now, making it almost impossible to find in the host basalt.

Most mines, where Datolite occurs, sport particular colors in their respective Datolites. I, and many other serious Datolite hunters can make educated guesses as to where a particular Datolite might have come from. I find my friend Jeff Anderson’s website the go-to site for Datolite ID. Check it out at http://www.sailorenergy.net/Minerals/MLDatolites/MineralMainDatolitesMI.html

Another rare Datolite is the Centenial, a white Datolite stained blue-green from oxidized copper. Several hundred pounds were removed, from a muddy pocket deep in the mine, in 1962 by miners. This was all that were found, and after the mine was closed, it flooded. If you have one of these “Tidy-Bowl” colored beauties, you are fortunate indeed. All Centennial’s were either full of copper flecks, or had less copper, making them lighter blue. Some blues came from other areas, like the Phoenix Mine (Phoenix), and the Isle Royal Mine (Keweenaw County). Even though blues are found in other locales, the best blues have always been from the Centennial.

Mesnard in the classic colors Mesnard is famous for.

Quincy Caramel!

Caledonia Mine. The red is Microcline (var Adularia)

Beautiful and striking Datolite colorations came out of the Mesnard, Franklin, and the Quincy. These three mines were eventually tied together by adits. The Orange/pink/red combinations are amazing from the Franklin and the Mesnard, as is the caramel Yellow’s from the Quincy.

Datolites of all colors were prolific at the Delaware and Connecticut Mines over the years. Many of the mine waste piles, including the Delaware, have been crushed in the last few years for road fill. Finding any Copper Country mineral is not as easy as in years past, mostly because of the incessant crushing of the old mine waste piles.

Bonnie found a wonderful bag of Datolites, I obtained several years ago, in my shop. I thought you would enjoy what I’ve been doing with them.

My Datolite jewelry is very popular at Copper World in Calumet, on our website, or see us every year in August at art shows in Eagle Harbor and Copper Harbor where you can choose your jewelry (Including Datolites) in person. All the types of Datolite’s mentioned in this blog are still available from us, but are becoming depleted as people realize if they don’t get one know, they may never get the ones they want.

Agate Expo-Part 2

Poppy Jasper-California (Kevin Ponzio Collection)

More amazing displays from the Agate Expo. Enjoy; it was better in person.

Priday Plume Thundereggs-Oregon (David Marshall Collections)

Cathedral Agate-Chihuahua (Pat McMahan Collection)

Parcelas Agate-Chih, Mexico

Montana Moss Agate

Kentucky Agate-John Leeds Collection

Scott Wolter Collection

Lava Cap Thunder Egg-Spanish Stirrup Roc Shop

Eye Agates-Don Kelman Collection

Fossilized Coral-Tampa Bay

Wingate Plume-Death Valley California (Tom Wolfe Minerals)

Dryhead Agate (Gary McFarlane Collection)

Mad River Agates-Madagascar (Brian Costigan)

Chinese Agate-Joshua Ritter Collection

Chinese Agate-Joshua Ritter Collection

Selling Jewelry at the Amazing Agate Expo

One of Tom Herman’s many Agates with Pictures

A view from the top of a chair

This is the third International Agate show held in the Midwest, and we have been vendors at each show. (Wonderful World of Agates and Celebration of Agates were the others). If you search my blogs, they are covered in them. Vending at this show was by invite only, so we were honored to be again included. This show was promoted by Veronica Woods, President of the Gem Shop in Cedarburg, Wisconsin.

The Cedarburg High School provided a great venue with the sales in the gym and the exhibits down at the pool end. The exhibit hall was exceptional, well laid out and labeled with a great variety and examples of agates from around the US and the world. I will write more about these another day, and I took many pictures.

Crowds were delighted but the predicted crowds of 10,000-20,000 never materialized.

Scott Wolter showing me one of his awesome Lakers

Our booth was positioned by Scott Wolter’s Lake Superior Agate and book sales. He has written the following books: The Lake Superior Agate: Fourth Edition (2008/2011)
The Hooked X: Key to the Secret History of North America (2009)
The Lake Superior Agate: Fourth Edition (2008)
The Kensington Rune Stone: Compelling New Evidence (2005)
The Lake Superior Agate: One Man’s Journey (2001)
The Lake Superior Agate: Third Edition (1997)
Ettringite: Cancer of Concrete (1997)
The Lake Superior Agate: Second Edition (1994)
The Lake Superior Agate (1986)

He also had agate puzzles and posters as well as his Lake Superior Agates.

Janet Wolter (Scott’s spouse) was autographing her book, America: Nation of the Goddess

Roger Clark talking Fairburn Agates

Our other neighbor was my friend Roger Clark, the authority on South Dakota’s beautiful Fairburn Agates. He was selling Fairburn’s and selling his books:
Fairburn Agate: Gem of South Dakota
South Dakota’s Fairburn Agate

Also in our block of 4 booths was the Gitchee Gumee Museum. Karen Brzys had her agates and agate art as well as her books Agates Inside Out and Understanding and Finding Agates.

Authors and experts abounded at this show, each presenting seminar programs and signing their respective books.

Snob Appeal Jewelry all lit up.

There were three wire jewelry artists at the show including me, but each had a different style. We had many comments and compliments. Bonnie & I had worked hard to really offer a wide selection of agates and jaspers in our jewelry. People seemed to appreciate our quality and there are many new owners wearing our jewelry; pendants, necklaces, bracelets, and earrings. I was proud of our display.

I decided for this first blog I’d concentrate on some Mexican Agates.

Laguna Agate, Chihuahua, Mexico (Brad Cross Collection

Royal Imperial Jasper

Flame agate. Jimenez, Chihuahua, Mexico

Luna Agate-Chihuahua (Stewarts Gem Shop)

Mexican Crazy Lace, Chihuahua (Mark Boche Collection)

Agua Nueva

Close-up of above

Luna Agate

Coyamito

This is the first of a couple blogs on the show and I will concentrate a little on the show and a lot on the killer exhibits, so come back again.

I hope I got everything right. It was really overwhelming.

Dinosaur Gembone Jewelry of the Pink Variety

When the dinosaurs died they probably didn’t know that years later their bones would be prized for fine jewelry making!

You can easily see the bone cell structure in fine Gem-grade Dinosaur Bone.

I acquired a slab of delicious pink/black/gray Gembone this year in Tucson. It took some slight prying and good money, but I’ve never seen quite this color in D-Bone, and when held up to the sun, you could see right through it in spots.

Dinosaur Bone is like Petrified Wood, in that the cells and patterns are replaced by varied colors of silica, making each cell a tiny agate. Some colors, like gem reds are more coveted that other unusual colors both in D-Bone and Petrified Wood. This piece has a great combination of white, gray, black with hints of pink making it very unusual.

The original slab (picture taken in natural sunlight). You can see why I wanted this one.

It is really an amazing gemstone. My pink slab was large enough for several cabochons. I am now working on several pendants of D-Bone (Not just this one slab, but many including some red).

Here is the first of my pendants Made from the pink bone. This Pendant was gold and silver and is about 3″ tall. it has a free swinging bottom, of a design engineered by me. This pendant was a real challenge and took several hours, but I think the effort was worth it. It is going to the Agate Expo with us to sell. Other dinosaur bone pendants and coprolite jewelry are for sale on our Dinosaur Jewelry page.