Welcome back everybody to Gemology for Schmucks. Here we are in episode 10
Congratulations you made it. So did I. Today we're gonna go back to basics a
little bit. We're gonna talk about why there are so many names for gemstones. So
we're gonna use these gemstones that I have in front of me, but I want to tell
you a little bit of a story. Back in the day they didn't have all these
fancy-pants tools that we have now. What they would do is they would take a stone
and they would look at it and use their senses. Right?! I know. It's preposterous.
How dare they. So what can you actually rely on if you don't have gemological
tools well you can rely on color, which is what we're going to talk about today.
Where does color come from in gemstones? Other things you can rely on is the
surface reflection. Different minerals have a different capacity to reflect
light so some will reflect more light and give you a bright or sparklier
surface and others will be a little bit more muted a little bit more calm. Other
things are how it feels in the hand. Some of them will feel heavier in your
hand like topaz for example, and others will feel substantially lighter like
emerald. So today we're gonna focus on color. Where does color come from in
gemstones and how does that relate to the names of gemstones. Throughout
antiquity as they were looking at these stones and they see that the color in
some of these stones is wildly different they just give it a different name right?
Blue ehhh... we call it aquamarine. Why?! It looks like water.
simple enough they look at this stone they say it's aquamarine it looks like
water we're good and then they find something that is golden yellow, so they
call it... let's name it after the Sun, so this one's actually called Heliodor.
They have all of these names because the colors are completely different. You got
blue, blue name. Got yellow, yellow name. but they can also tell that there's
different types of yellow stones this one and this one they may have similar
yellow colors but this other one feels much heavier it can't possibly be the
same stone right? You're right. and so they give them different names. But later,
as history goes on, and fancy-pants tools come around and people like me who have
the ability to test them, we find out that some of these stones that have
vastly different names are actually the same mineral. So in the minds of people
they are a different stone but as far as the earth is concerned it's all the same
thing. So let's look at some stones and hopefully this will give you the mental
shelves to understand and why some minerals can look so vastly
different and other minerals will always look a certain way so once you've got
this logic hopefully it'll make your life much easier let's go
These stones have more in common than they have in difference. In fact, aside
from this pink one over here, they are all the same mineral and even this pink
one is still basically like a half brother. We'll think of it that way. So
these are all a mineral called Beryl we see them as completely different and the
ancients gave them all different names. So these blue ones down here we call
aquamarine. These yellow ones we call heliodor. The greenish ones can be
either aquamarine or heliodor depending on which color is dominant. If it's the
blue or if it's the yellow that's dominant. The green is emerald and the
pinkish hue over here a little bit peachy is morganite named after JP
Morgan the famous financier. How does this color come about why is it that
this heliodor is yellow and this aquamarine is blue. The truth of the
matter is that there's tiny trace impurities that give it that color
Beryl in its chemically pure form is actually colorless. It's a variety called
goshenite. We don't have that in the shop, but goshenite is absolutely without color
and when it gets a little bit of a color we change its name to one of these that
you see right here. So heliodor, how is it that heliodor is this wonderful
golden yellow color. Sometimes they call it golden beryl. Well it gets its color
from iron so when there's trace amounts of iron in the crystal lattice it gains
this lovely yellow golden color and the same thing actually with aquamarine
aquamarine is also colored by iron. Now, how can it be both yellow and blue? Such
distinctly different colors... There's a high science explanation but it's
something called valence. It's basically how ready to bond that element is so
iron with certain amounts of electrons that are available for bonding will
cause different colors in these stones back here with the morganite this is
colored by manganese, so manganese is what gives it this peachy pinkish color.
and finally emerald and emerald can be colored by a couple of different things.
M ost often emerald is colored by chromium sometimes it's also colored by
vanadium or a combination of chromium and
vanadium and that's what gives it its different color. The real takeaway that I
want you to get from this episode is that some gemstones they have a special
name because of a color and that color is not always an important part of what
that mineral is. So a gemstone like emerald or heliodor or aquamarine has
its place in human culture because of what you could consider almost an
accident it's a trace element impurity. This
watermelon tourmaline right here really helped me to understand the influence
that the growing environment of the crystal has on its color because you can
see right here that this area is pinkish reddish and then this is green. The same
on these back here you can see that one side is green and one side is pink. When
the crystal was growing it had certain nutrients available to it that created
this reddish area and then in a different stage of the crystals growth
it had these elements available to it that created this green in the crystal
and if we look at it from here you can actually see that there's a colorless
area right in the middle and that shows us that during the crystals growth it
lacked a certain amount of nutrients and so it had nothing to give it color so it
just remained colorless. A great example of allochromatic gemstones is corundum. So
this is Ruby and Sapphire right here. And right here these three you can see are
nearly colorless... They might have a little bit of color, but just the
faintest amount. In its chemically pure form these would be colorless so you can
tell that there are very few outside influences as far as elements that would
have switched into the crystal structure and the chemical composition whereas
something over here like this bold ruby is intensely red and this down here is
intensely blue so you can tell that there's a lot of extra elements that are
substituting into the stone and that's what gives us the strong color here also
we have those oh so familiar zircons. These also are allochromatic gemstones.
You can have blues you can have yellows reds greens oranges and also colorless
If there's a colorless variety of the stone that's a huge giveaway that it's
an allochromatic gemstone because if it was idiochromatic, that means that
something in the chemical composition is going to give it color. A classic example
of idiochromatic gemstones is right here peridot all of these are peridot and
once again it's iron that's causing the green in this. The reason it's an
idiochromatic gemstone is because iron is an important essential part of the chemical
formula of peridot so the stone that peridot is will always have iron in it
therefore it will always be some shade of green, greenish yellow, sometimes
there's a hint of blue, but it's always going to have some kind of a green
component. Right here, spessartite or spessartine garnets. Sometimes people
call them Mandarin garnets and these four pieces are a mineral called
rhodonite. Now both of these in their normal chemical structure have an
element called manganese and manganese, in a lot of gemstones, will create either
an orange or a pink or a red color and that just depends on how much manganese
is in the crystal structure. Here we have two pieces of Persian turquoise and
turquoise is always some sort of a blue or a green. Turquoise has copper in its
chemical formula and so that always creates some kind of a blue or a green
and that's why we call it an idiochromatic gemstone. The key thing to
remember is that there are stones that are colored by their normal chemical
formula and that will always have a typical color and then there are other
stones that are colored by outside impurities. Some things have a different
name but they're actually the same mineral as something else and the names
are just there as distraction. But it's not all just smoke and mirrors right?
you can see that as humanity interacted with these stones from the earliest of days
that they built up this mythology. They built up his idea of this stone is
different from that stone and that's not always connected to science sometimes
it's connected to witchcraft. I mean to be fair I mean if you see a type of
quartz and you don't know it's a type of quartz it's just green and got spatters
of blood on it, you call it bloodstone. To not do so would be wrong. So when you
know that there's about 25 different names for different types of quartz, you
can just put that in a mental box and that will help you to know that okay
it's going out this kind of hardness it's gonna have this kind of luster it's
gonna have this kind of a blah blah blah blah and it allows you to focus on other
things that are more important like for example if you're talking about quartz
what's going to add value? You know it's going to be unique patterns for example
if it's some kind of an agate. You're not worried about the hardness you already
know that. You know what kind of reflectivity it's gonna
have. You know what kind of lustre it's gonna have. None of that's interesting
well what IS interesting is if it has a special pattern, that may increase the
price for you. Okay so hopefully this has helped to give you some mental
scaffolding and an idea of where to put these different gemstones in your mind
so thanks for joining me on Gemology for Schmucks. My name is Peter Nelson I appreciate you
joining me for this time as we expand our minds. Go enjoy your day~