The Corundum Family of Minerals
Sapphires and rubies are both variations of corundum. We tend to think of sapphires as blue, but they can be green, pink, yellow, and many other colors depending on the presence of different impurities.All colors of corundum are called sapphire except one: red corundum is always a ruby.
Mining Near Franklin, NC
In 1870, companies began mining corundum in Macon County. Second only to diamonds in hardness, corundum is used as an industrial abrasive. Commercial mining stopped when synthetic corundum became a cheaper solution for industrial needs. The mines were forgotten until locals and tourists became interested in them for another reason—finding their own rubies and sapphires.
The Sheffield Mine
We arrived at Franklin's Sheffield Mine about noon. Sheffield is one of our favorites, because visitors nearly always find at least one nice ruby or sapphire to take home with them.It's one of the few mines in the area that sells native dirt, straight from the earth with nothing added or subtracted. You might find a ruby, or you might not.
Most mines enrich the dirt with purchased uncut gems. Enriched buckets are a sure thing. They're a good choice for kids, or for adults who want to find a variety of gems. Sheffield offers enriched buckets of dirt, too, but they're kept in a separate area so that visitors know exactly what they are digging into.
Looking for Native Rubies
The mine charges a per-person fee that covers two large buckets of earth for each miner. Choose buckets filled with either native or enriched dirt, and if you feel like digging through more, buy a few additional buckets, because they're reasonably priced.
Take Your Buckets to the Flume Line
A flume line is a shallow trough with water running through it, kind of like a man-made, elevated creek. The running water helps you wash the dirt off of the materials in your bucket.
Looking for Rubies
Staff gives everyone a sifter box, a wooden box with a screened bottom that lets water rush out but keeps your stones inside.Pour some of the dirt in your bucket into the box and place it in the water. Swish the ingredients around with your hands and move the box up and down to help the water rinse the clumps of mud off the contents.
If you have an enriched bucket the job won't be too hard. Stones were probably clean when they went into the dirt, so what's there should wash off easily. Young children have a lot of fun with the enriched buckets, because the colorful gemstones are easy to seee when the dirt is rinsed from them.
Searching native earth for gems in their natural state takes more time and effort, and you'll need to develop a good eye for exactly what you're looking for. The dirt on gems in a native bucket has been there forever and isn't as easy to remove, and the rubies are still surrounded by their matrix, a crusty, gray, protective barrier.
- Push large rocks aside and gather smaller gravel into a mound at the center of your tray.
- Cup your hands over the pile and move it in a circular motion. The grinding action removes the dirt from the stones.
- Rinse your stones and rub again. Repeat the process until no more mud is visible on your hands. Linda Smith, one of the mine's owners, says you should always "rub and rinse one more time than you think is necessary."
Spread your clean stones into one layer and look carefully for glints of lavender or deep purple-red. Staff will show you examples of what you should look for, because rubies at this stage look nothing like the brilliantly cut gems we're used to seeing in jewelry stores. It might take a little practice to identify them, but once you've found a few you'll be off like a pro.
Check Everything in Your Sifter
Don't forget to check those larger chunks you set aside. Chances are they're just rocks, but Eugene King found a 488 carat ruby that nearly fills the palm of his hand. Here's a tip: a piece of corundum is much heavier than a plain rock of the same size.
Using Your Rubies and Sapphires in Jewelry
What can you do with your rubies and sapphires? There are many artisans in the Franklin area who will cut and mount the stones for you. Remember that when a gem is cut it does lose size, because the artist works around imperfections and determines the type and size of cut that will produce the most beautiful finished gem.
Star Rubies and Sapphires
The Sheffield Mine contains rare star rubies and sapphires, stones that produce a six-pointed star when they're cut into a cabochon shape, with a smooth, rounded, dome-like top. The star is the result of needle-like inclusions that react with light.It is so much fun to see how what looks like a plain grayish rock turn into a brightly colored gemstone, one you know is natural and untreated. Jewelry made from gems you've found yourself is special, even if the stone doesn't have perfect color or clarity.
You were the one who found that ruby or sapphire. You plucked it out of a pile of rocks that has been buried for eons. I guarantee that once you've found a few gems, you'll be hooked.
More photos of our finds.
