>>GEORGE HARLOW (Curator, Mignone Halls of Gems and Minerals): Geologists go and look at earth as
outcrops, things that are meters to hundreds of meters in scale. So for the mineral hall,
I thought that the idea of getting closer to nature by bringing the big, natural objects in
would both be exciting and also informative about the scale of processes that we’re talking about.
[MUSIC]
>>ELLEN FUTTER (President, American Museum of Natural History): The reopening
of these halls is particularly thrilling at this poignant moment in history.
It’s the return of a beloved treasure of the Museum and of the city.
And when visitors from all over the country and all over the world come to see these
gorgeously restored halls, they’re going to find remarkable specimens.
>>HARLOW: We probably have 128,000 specimens in the mineral and gem collections. In this hall,
there’s a little over 5,500 specimens; that’s more specimens than in any other hall
in the Museum. And I think when you people come here, it’ll become obvious, wow,
there are a lot of specimens, and the nice thing is they all tell slightly different stories.
>>HARLOW: Behind me
is an amethyst geode. This geode actually represents a giant bubble that occurred
in the middle of a layer of molten rock on the order of 130, 140 million years old.
The crystals that you see inside the geode are quartz crystals, and those are amongst
the first things to form, dissolved by water, and then precipitated inside the cavity.
In order to make quartz purple, you have to irradiate it. And so that takes a long
time to turn a quartz from a colorless quartz to an amethyst colored quartz,
probably on the order of many millions of years. So one of the cool things about this rock
is the timescales it represents. That bubble maybe occurred in a few minutes to an hour,
crystals, hundreds of years, then the amethyst, millions and millions of years.
But one of the problems with it is that it's got its front, and it's got its back. So, why don't we get another geode, we put them back-to-back,
and then you'll always be looking at the face.
The thing that I find most amazing is that whereas they both
come from the same place, they have very different characteristics, both in terms of color,
what’s going on inside of them. You know, they’re very, very different
from one another, and both signature objects for the hall.
>>HARLOW: This specimen is a block of the green mineral malachite and the blue mineral azurite.
Originally it was the centerpiece of an exhibition for the World’s Fair 1893. And after the exhibit
was finished, it was shipped here to the Museum as a gift. It’s 7,000 pounds, which represents about
4,000 pounds of copper, which is what its fate would have been if it had been left in the mine.
But it’s been preserved for us as our exemplar specimen from Bisbee Arizona which we actually
have a very good collection from. Now, why is it called The Singing Stone?
Back in the day when it was exhibited in the halls when there was no air conditioning,
it would start to squeak. The minerals have water molecules that can come and go out
of the structure, and when they do that the mineral actually changes its shape slightly,
and make little singing sounds. “EEEEEEEEEEEEEEE” things like that. I’ve never heard that,
because in general we’ve had the specimen under reasonably good conditions of temperature and
humidity. But if you raise the humidity a lot, then you start hearing it sing.
>>HARLOW: The slab behind me
is a big piece of, actually marble, but it’s an ore-bearing marble
that comes from Odgensburg, New Jersey. I knew that the fluorescence from this locality is
famous world-wide, but specimens that give you the scale, don’t exist. We hired stonecutters
from Italy who used wiresaws and we sliced through it like a piece of cheese.
Fluoresence is the property where you shine ultraviolet light on something and the energy
release is equivalent to the wavelength of light. You can see the layers in it–willemite,
which glows green in ultraviolet light, and the calcite which is the limestone part of it,
glows a bright orange color. So this is like a layer cake. You can actually see
the age through time. And so the idea was not only to have like this incredible scale
of what you could see, but also the details of what the geology is there.
>>FUTTER: The minerals throughout these galleries are so spectacular,
so multicolored, so indicative of the diversity of forces and life on Earth,
and they represent a treasure trove for demonstrating the importance and the power of our planet.
So there’s something for everyone that’s familiar and new,
and it will be a great fun for all— and a great learning experience, too.
[END MUSIC]