Have you ever seen a beautiful gem resting delicately on a ring or hanging radiantly from a necklace?
Let's explore the process by which these humble rocks transform into priceless jewels.
When certain mineral crystals are extracted from rock and then cut and polished, exquisite gems are created.
Mineral crystals may grow in or on rocks.
Some may solidify out of evaporating water, but it takes a skilled eye to spot
these beauties, to know which ones are valuable, and to turn them into refined gemstones.
Gem-bearing rocks are extracted from the mines, washed, and then sent to a facility to be further processed.
Raw gemstones are easily overlooked because they don't look at all like the polished jewels you see in jewelry.
Gemstone miners must search very carefully to spot the diamond in the rough.
Next the gem cutter, or the lapidarist, will follow a series of steps to grind, sand, and polish the gems.
Then the gemstones are placed in a tumbler to be smoothed and polished even further.
After a gem has completed this refining process,
how does a gemologist determine how much money the gem is worth?
This depends on the 4Cs; cut, clarity, color, and carat.
Let's take a diamond for example.
There are many different shapes into which a diamond can be cut.
A skilled lapidarast will take into consideration that a diamond's cut affects how bright the diamond looks.
This is because the cut influences how light travels through the diamond.
The fewer flaws such as chips, abrasions, or cloudiness that are found in a gem, the better its clarity.
The color of a diamond commonly ranges from yellow to white.
There can also be other colors such as blue, brown, pink, and very rarely, even green or red.
Finally, carat refers to the gem's weight.
The 4Cs are important for both the buyer and the seller.
It's common for precious gems to be passed down from one generation to the next.
Geodes are like little inconspicuous treasure chests. The word geode is Greek for, "earth-like" and while they may
appear to be plain, old rocks, when they're opened up, the insides reveal shimmering crystals.
When the geode is cracked open, these crystals are found lining the rock's hollowed out center.
You may be wondering, "why are these rocks hollow?" and, "how did crystals get inside?"
Geodes are most commonly created as molten rock hardens and forms crystals.
Rocks formed this way are called igneous rocks. As the igneous rock forms, the outside cools faster than the inside.
Within in the rock, gases and water vapor are trapped, forming a cavity.
Inside this cavity, dissolved minerals collect and begin building crystals.
From heat and molten rock a beautiful and unique geode has formed.
Geodes can also be found in another type of rock called sedimentary rock.
Sedimentary rock forms on, rather than in, the earth as small pieces of rocks called sediments are compacted together.
Organic material which comes from living things such as wood or animal bones gets buried within the layers.
When the organic material breaks down, a hollow cavity is left within the sedimentary rock.
The outside layer of the rock has tiny holes that allow mineral-rich water to
pass through, leaving its minerals behind in the rock's cavity.
Over time, these minerals grow into larger crystals inside the new geode.
Geodes can be found in an awesome array of colors and sizes.
Geodes can be as small as a golf ball that fits in the palm of your hand, but others are incredibly large.
It's common for geodes to be confused with another type of rock.
Can you see a difference between these two rocks?
An agate is a colorfully banded gemstone found within a host rock with no hollowed center.
However, geodes can form in many different types of rock, even agates.
So if a crystal filled cavity is found within an agate, then that agate would also be called a geode.
How fascinating it is that what seems to be just an ordinary rock can actually contain such dazzling beauty.
Maybe you are feeling the sudden urge to go out and discover what surprises may lay inside the rocks near your own home.
If so, you are well on your way to becoming a geologist.