G is for Geodes

I was going to write about gold here, but this is more interesting and there are some facts here that I bet you’ll be surprised about.

Unopened geode - see how plain this is

This is a geode sliced open.  Sorry this pic is in black and white

Geodes are agates that got their name from “achates” because the first one was found near the river Achates in Sicily.  Agates come in a wide variety of colors and patterns.  One must be careful buying them because this stone is easy to dye and the bright, gaudy ones aren’t natural colors.

A geode slice

But how they form is the really cool thing about agates.  They occur as a cavity filling in lava.  If a bubble of gas forms in the lava when it hardens this bubble fills up with silicates.  This is called geode.  You can buy whole geodes, which look dull and like a lump of rock but once opened they glisten with quartz crystals, which can be in many beautiful colors.  It’s truly a feast for the eyes that something so stunning can be on the inside of something so plain and ordinary. 

Here are more sliced geodes

I’m sure many of you have seen these around in souvenir shops, or at gem fairs.  They are strikingly gorgeous and make good bookends, or a conversation piece to sit on a shelf.

And look at this one.  Isn't it pretty?

You can also buy flat “slices” of geodes, which show patterns to their best effect.  When the geode fills up sometimes it hardens in layers of different colors.  If there’s a gap more quartz crystals may grow.  These flat pieces make excellent jewelry.

F is for Flint

Flint is opaque and brown or black.  It’s the most common of silicates.  In the Stone Age people used flint to make tools.  If skilled at using flint one can make axes, arrowheads and other tools.  Use caution as it does flake and break easily.

Flint arrow head

Raw flint

Another piece of raw flint

Tinder boxes and early guns had flint to produce a spark.

Sometimes flint is used in buildings.  In East Anglia in England there’s no other building material.  Flint doesn’t wear as it’s hard, so using it makes it almost impossible to tell the age of buildings in Norwich where it’s a common building material.  Sometimes it’s mixed with other stones and rubble.

A building with pieces of flint on the front

And this is the coveted item everyone wants in the television show Survivor and is usually the first thing they get if they win a challenge.  Fire is essential in order to cook food and boil water.  I’m a big Survivor fan and have watched every episode since the show started in May 2000.

E is for Emerald

This was covered in B under beryl so I had to do some more digging to find more info on this one.

Impurities in beryl cause different colors that create different gemstones.  Beryl is a colorless mineral, but when chromium is added it becomes green and emerald.  Beryl with iron added becomes blue and is then aquamarine.

Isn't this beautiful?  This is from Musa Columbia

Emeralds are hard, but inclusions (flaws) can cause them to crack.  Sometimes gemstones are heated to increase color and clarity.  Of course caution has to be used during the heating process.  

I found this fact interesting.  Emeralds with fissures are treated with wax or oil that is colored.  This creates a stone with more clarity thus making it more desirable.

Raw uncut, unpolished emerald

Gemstones can be natural or lab created (synthetic).  It’s almost impossible to tell the difference between the two.  But synthetic gemstones are usually more perfect in color and clarity because they weren’t created by nature where impurities exist.

Most of the largest emeralds are in museums or private collections.

Most of the info and photos are from Wikipedia, GIA and Gem Select websites.

D is for Diamond

I guess nothing much needs to be said about this.  We all know what diamonds are.  Let’s see if I can give you some facts.

Diamonds are just carbon, the same element as graphite.  Diamonds are the hardest natural material because the atoms are locked together.  It’s harder than any man made material.  They can be used industrially for cutting, such as diamond saw blades.

Cut and polished diamonds

Cut diamonds sparkle in the beautiful colors they reflect when they catch the light.  The diamond market is strictly controlled, even making the uncut ones valuable.

Diamonds were traded and taxed in India before 300 BC.  So they even had taxes way back then.  Good grief!  I guess taxes have been around forever.  Diamonds were exported by sea or land along caravan routes.

Uncut and unpolished diamond

There are several famous diamonds in the British crown jewels that were presented to Queen Victoria.

Diamonds are the stone of love, yet they are the hardest mineral known and can scratch anything.  Is there a hidden story in that?  I wonder.

C is for Copper

Copper is both shiny and opaque.  Being a metal it’s also quiet heavy.  This is probably the first medal used by man.  Copper was found on the island of Cyprus so many think this is where it gets its name. 

Raw copper

The metal copper makes bronze when mixed with tin and was used before iron was in general use.  Today it’s used in wiring and water pipes.

While living in California we had all our plastic pipes replaced with copper after the plastic burst and flooded the house.  What a mess that was.  And of course this “adventure” happened over Thanksgiving.  The house was torn up for weeks.

B is for Beryl

Pink beryl

Beryl can be green, blue, yellow or pink.  It’s a transparent crystal.  If it’s green, it’s emerald, blue is aquamarine.

Green beryl not yet cut and polished

The green form, emerald, has been valuable for a long time.  It was mined in ancient Egypt from the second millennium BC until 1370.  India and Europe received all their emeralds from Egypt.

Aquamarine beryl in quartz

Aquamarine beryl

The name aquamarine wasn’t used until the sixteenth century.  Long ago it was a sailor’s talisman.

A is for Alabaster

This is a mineral that’s been around since ancient times.  Back in the Roman era it was carved into vases, used as monuments and windows in churches and made into vessels.  The purest form is snow white with a fine uniform grain and is thin enough to see through, thus making it suitable for windows.

Artifact in the Egyptian Museum Cairo 

The origin of “alabaster” is from the middle Ages, but it seems no one knows exactly where this word came from.  Some say old French, others say Latin, and still others say Greek or ancient Egypt.

Alabaster is soft so carves easily, but this quality also makes it unsuitable for outdoor work.  Fine alabaster is used as ornamental stone, especially in cathedrals and on stair rails, vases, etc.

From the Roman Empire

Alabaster is porous so it can be dyed into any color by immersing it into the dye bath and heating it to certain temperatures.  Caution must be used, however, because it can be easily ruined by too much heat and that causes the stone to have a milky white look much like chalk.  This ruins its translucent appearance.

Fossanova Abbey in Latina Italy

Gypsum alabaster is the softer of the two alabaster types.  The other is calcite alabaster found in caves.  Gypsum alabaster artifacts have been in Egypt.  They date back to the late fourth millennium BC.  Gypsum alabaster can also be found in Spain, Italy, England and Wales.

There is also a rare black alabaster that can be found in only three places in the world, Oklahoma, Italy and China.

All pictures courtesy of wikipedia