Colorful Stories of Three Colored Gemstones

The romance and history of colored gemstones has always fascinated me.  I guess I’m just a sucker for a good story.  Here are three I thought you might like.

TANZANITE:  It’s said that we are all members of the “Tanzanite generation.”  Discovered in 1967 by a Masai tribesman in Northern Tanzania, Tanzanite is mined in only one, 4 square kilometer, location.  And the mines are getting deeper and harder to mine profitably.   We will be the ones who can buy a new Tanzanite.  Future generations will only see the stone in heirloom pieces.  It’s estimated that Tanzanite One, the largest Tanzanite mining company, has less than 30 years of production left.

The gemstone was named by Henry Platt, great-grandson of the famous Louis C. Tiffany.  Tiffany and Co. realized the importance of the gemstone and quickly made themselves the main distributor.  Their marketing efforts made tanzanite one of the most popular gemstones by the 1990s.  The beautiful gem hit the big screen with a “splash” as the Heart of the Ocean in the movie, Titanic.

KateWinslet

MORGANITE: This pink to orange/pink variety of beryl was originally discovered in Pala, California in the early 1900s.  It was named for J.P. Morgan, a great financier and collector of minerals.  Tiffany’s gem buyer and gemologist, George Kunz, was the man who named the gem, buying up all he could find for his wealthy client.  Incidentally, another pink gemstone, discovered at about the same time, was named Kunzite in honor of George Kunz.  So, he got his own gemstone, too!

Morganite is the same species of mineral as Emerald and Aquamarine.  Like Aquamarine, it is usually an eye-clean stone that can be cut in larger sizes.  It’s a good thing, too, because a larger stone usually shows a more saturated color.  Pale Morganite often needs that advantage.   It’s generally heat-treated to improve its pink color and minimize its yellowish tint.  The treatment is stable, so no fading occurs. morganite2

ALEXANDRITE: First discovered in Russia’s Ural Mountains in the early 1830s,  Alexandrite is the quintessential color-change gemstone.  It was found by miners who thought they’d found emeralds, until nighttime came and they were sitting around the campfire.  Alexandrite’s trace elements of iron, titanium, and chromium make it greenish in sunlight and reddish in incandescent or fire light.  Boy, were those miners surprised when, the next morning, their red gemstones had turned back to green!

Legend says that the gem was found on the 16th birthday of young Alexander II, future Czar of Russia.  The stone became the National Gem of Czarist Russia.  It was the perfect fit with the red and green color scheme of imperial Russia’s military.  Every Russian had to have an Alexandrite.  Unfortunately, for all of us, the Russian supply was depleted.  Fortunately, other deposits have been found in Sri Lanka, East Africa, and Brazil.

Natural Alexandrites are very expensive, especially in larger sizes.  Even the synthetic version is expensive, because it’s difficult to manufacture.  But, if you’re lucky enough to own an Alexandrite, you have an “Emerald by day, and a Ruby by night.”

alexandrite

The Story of Campbellite

campbellite

I’ve lived most of my life in Michigan and my maiden name is Campbell.  Most people don’t know that because I’ve been married so long!  But I always thought Campbell was a good name, so I was both happy and surprised to learn that there is a gemstone named after. . .no, not me, nor my kinfolk, but after the Campbell shaft of the well known Bisbee Mine in Southern Arizona.

So, what’s the story of Campbellite?  As explained by one of the stone cutters at Arizona Lapidary, Campbellite is an uncertain  mixture of minerals like cuprite, azurite, malachite, calcite,chrysocolla, pyrite, quartz, and copper.  Its color and look varies because there’s no set amount of these minerals.  It was first discovered by miners looking for copper.  The bosses weren’t interested in this unusual rock, and told the miners to discard it.  But the miners had a different plan.  They saw its beauty.  So, yes, they dumped the Campbellite in the trashcan.  But they separated it carefully from the real trash.  And when no one was looking, they loaded the discarded gem into the back ends of pickups.  Campbellite has been showing up in the market, piece by piece.  There’s not a lot of it–I’m sure plenty WAS dumped.  The mine closed in 1975, and there is no other known source of Campbellite.  But I bought one piece of it, cut into a smooth cabochon, and plan to make a bolo tie for my dad.

I learned a little bit about the mine shaft itself.  It was first developed in 1927, originally as a way to get oxygen to other parts of the Bisbee Mine.  But soon it was one of the best producers of copper ore, with yields of 8-10% copper.

Finally, who is the Campbell shaft named after?  A little research revealed an amazing coincidence.  The shaft was named after Gordon R. Campbell, who actually lived and went to school in Michigan!  He graduated from U of M in 1893 and was a mining executive and lawyer up in the Keweenaw Peninsula.  The Keweenaw Peninsula, jutting from the Upper Peninsula of Michigan, is one of the best known sources of copper world-wide.   Towns like Calumet, Houghton, and Copper Harbor were booming back in the mid-1800s because of copper.  Anyway, Gordon Campbell helped form the Calumet and Arizona Mining Company in 1901, serving as the company’s President from 1921-1931.   It was this company that operated the Bisbee Mine.  So Campbellite WAS named for a Campbell living in Michigan.  Who knows?  Maybe he’s a long, lost cousin?

The Campbell shaft, courtesy of the Arizona Historical Society

The Campbell shaft, courtesy of the Arizona Historical Society

 

 

 

 

 

 

Minerals of Michigan

Lake Superior Agates

Lake Superior Agates

If you’re a Michigander like me, you grew up going to one of the Great Lakes for a day at the beach.  As a kid, I didn’t know how lucky I was to witness the variety of minerals and rocks along the lakeshore.  No where else in the world can you see that variety.  I would look for our state rock, the Petoskey stone.  I didn’t even know that Michigan had a state gem, the Isle Royale Greenstone (aka Chlorastrolite.)

I’ve always been a rock hound of sorts, and many Michiganders share my passion.  There’s so much to know about our rocks and minerals.  Most of the information in this post comes from a great book called, Michigan Rocks and Minerals, by Dan and Bob Lynch.  I’d highly recommend it if you’re a serious rock hound.

Their book brought up questions I’d never considered before.

*What’s the difference between a MINERAL and a ROCK?

A mineral is a crystallized version of a chemical compound.  Most gemstones are minerals.  For example, a diamond is crystallized carbon.  Quartz is crystallized silicon dioxide.  Rocks are a conglomerate of minerals.  Lapis Lazuli is an example of a gem that’s actually a rock.  Its main ingredient is lazurite, but it also has minerals like calcite, pyrite, and mica.  While minerals have characteristics, such as hardness or refractive index, that can be identified throughout the mineral, the characteristics of a rock vary depending on which spot of the rock you’re testing.

*What’s the difference between rock hunting in the Upper Peninsula vs. the Lower Peninsula?

The U.P. and L.P. are geologically very different.  The U.P. is formed from volcanic rock.  It is rich in the elements of copper, iron, manganese, and even gold.   Those elements lend themselves to minerals like azurite, chrysocolla, and hematite. The L.P. is formed from sedimentary rock.  It has a lot of limestone, shale, and gypsum.  Most of the pretty Michigan minerals, in my opinion, are found in the Upper Peninsula.

*What are some basic tools needed to identify rocks and minerals?

If you do want to do some rock identification, you’ll need a few simple tools.  Of course, an identification book is necessary.  But one of the main ways to identify a rock is by its hardness.  The Mohs Hardness Scale measures minerals from 1 to 10, with one being the softest and ten the hardest.  Most minerals in Michigan fall between 2 and 7.   You can estimate a mineral’s hardness using a scratch test, taking care to scratch the specimen in an inconspicuous place.  Your fingernail will scratch a mineral of 2.5 hardness or less.  A copper penny will scratch a mineral of 3.5 hardness or less.  A piece of glass or a steel knife works on minerals of 5.5 or less, and a piece of unglazed porcelain works on minerals of 6.5 or less.  So these four inexpensive tools can really help you narrow down the options when you want to identify your find.

Michigan Rocks and Minerals discusses over 200 different materials, giving details such as hardness, common size, and color.  The book has color photos of the materials and gives suggestions of where to look for them.  I’ve decided I want to look for Lake Superior Agates, Dolomite, and Pudding Stones next summer when I go to the U.P. Wish me luck!!

Pudding Stone

Pudding Stone