last time on IDU curiosity we explored examples of Australian opal this time
we're gonna see opal from all over the world I caught up with Jenni at the
Australian opal Centre in Lightning Ridge for a world tour of opal
once again these pieces have been chosen for their representative and scientific
value so they're not always gem quality but I'm sure you'll agree that they're
all beautiful specimens other than Australia one of the better-known opal
localities or opal producing countries is Mexico Mexico is most famous for
what's called fire opal it's called fire opal because it tends to have a fiery
body tone or color that these are just beautiful little beetle shaped pieces
I think it's rhyolite, the host material it's a volcanic or partly decomposed
volcanic rock within each of those is a lovely little piece of Mexican opal you
can see some of them we've got a lovely warm fiery orange body color which is
quite different to most Australian opal although there is some really fantastic
fire opal coming out of Western Australia now with this reddish to
orange body tone and here's some little rough pieces a lot of it is common opal
or potch without any play of color but you can see in some pieces little twinkles
of spectral color which is precious opal amongst the potch the like Australian
opal the potch can go right through to white you can see that a lot of it
instead of being on the white to black spectrum using this warm orange tone
this is an unusual piece of Mexican opal that's been carved and it has a
colorless body rather than the fiery body and beautiful little rainbows of
precious opal color on it I find that watery clear colorless material really
really enchanting and also from Mexico our three little faceted pieces not much
in the way of play of color but really pretty and just showing three different
body colors or body hues in the Mexican opal the colorless one has some cracks
in it so it's dehydrated over the time since it's been cut from another area of
Mexico here's a another piece of volcanic rock
has a really cute little blue green sparkle of opal in it a bit of purple
there too so that's Mexico another place in South America that produces some
really beautiful opal is Brazil here are two little chunks of rough Brazilian
opal that don't have any play of color so that's a colorless Brazilian potch and
here is another piece of Brazilian rough that's got a cloudier body and I'm not
sure if you can see but it actually has a little bit of green and purple see if
I just get some opal making water, dipping sauce, otherwise known as
Lightning Ridge bore water once I wet it you can see that there's a little bit of
color in there here is a gorgeous piece of carved Brazilian crystal opal very
similar really to crystal from South Australia various fields in Lightning
Ridge white cliffs interestingly it is a little bit heavier so it's got a
slightly higher specific gravity so that little piece would probably weigh more on
the scales than somebody used to handling Australian opal would expect
here's another little Brazilian carving in a white opal or a light opal really
rather than white and something completely different here is a piece of
faceted green translucent potch also from Brazil so it's interesting we've seen
potch from Australia that really tends to be on the white to black through gray
scale with Mexican opal there tends to be a warm fiery glow orange to red body
tone and here we are with a translucent common opal from Brazil with a green
body tone sticking to South America here is opal from Peru this is called pink
opal it's Peruvian pink opal and it is potch again or common opal but it has
this lovely rose-colored tone to it and in a similar vein there is
also a Peruvian green or blue opal so here's a lovely big chunk of that
sometimes there are dendrites in this Peruvian material and its prized to try
and find the dendrites and cut a stone with the dendrites on the face dendrites
are little feathery blackish inclusions like seen in various agates and
sometimes in common opals from elsewhere so so here we have two beautiful really
different colors of common opal different to what we expect in Australia
these are these are quite opaque if we cut little pieces of this and polish
them the light wouldn't pass through it unless it was a really thin slice but
sometimes it can be translucent this is Peruvian material potch that's been cut
into beads even common opal or potch can be absolutely beautiful as a lapidary
and jewelry material I think that's just lovely all right
Honduras this is a type of matrix opal this is from the Honduras area so this
is volcanic rock that has opal permeated through the rock very finely distributed
so if I add a bit of water to this we probably get a better look at the opal
play of color so that piece has some lovely Reds golds flecks of different
color through it now Honduras produces other material that has more opal to
rock and this is largely rock with the opal permeated through it but there's
some lovely Honduras material also that can take a lovely polish so similar sort
of idea to Australian matrix opal from Andamooka or from the Queensland fields
we've got the opal in the tiny little pores between
the particles in a porous rock heading north there are a number of
sites in North America or States that produce opal probably the best-known
location is Virgin Valley in Nevada and it's particularly famous for producing
opalized limb casts so this is a tree structure a limb from a tree that's been
preserved as opal but really neat piece that this is a slice through a limb cast too this has been coated with resin to stabilize it so some of the Virgin
Valley material tends to dehydrate and this piece has been given a quick coat
of resin to trap in the moisture but you can see the beautiful play of color this
does qualify technically as black opal that's quite different to Australian
black opal and because of that tendency to dehydrate it's regarded quite
differently but what a spectacular piece and here's another limb cast from Nevada
this is completely untreated just love this turquoise color here and then the
other side's really fascinating too so Nevada one location for opal in North
America that probably not a lot of people know about is Louisiana here's
some material from Louisiana and again this is a type of matrix so it's a very
coarse grained stone that has opal sort of almost like soaked in so the silica
rich water has soaked into the rock and over time formed opal so you can see a
little bit of play of color there that's Louisiana and here is a small piece
that's been cut and polished this is also from Louisiana so that's a matrix
opal from Louisiana in the United States there's also opal found in Oregon Idaho
and a few other states heading north again here that's a piece of opal from
Canada I don't think many people know there's
opal found in Canada either but again this is a type of matrix opal so it's a
volcanic rock that has many many little tiny gaps or vesicles in it that have
later filled up with opal let's go to Africa probably the best-known opal
location in Africa is Ethiopia I have some examples of rough
Ethiopian opal the body tone in Ethiopian opal could be anything from
very light to quite dark so these are little chunks of Ethiopian opal in these
little nodules and this material has got a reddish brown sort of chestnut brown
body tone so that's rough Ethiopian opal in an opaque browny body color and
darkish body tone and this is like Ethiopian rough opal I'll just put a bit of
water on those they haven't been polished yet so untreated still in the partly decomposed
volcanic rocks that it's formed you and this is an unusual piece of polished
lighter Ethiopian opal with a light kernel inside a translucent crystal or
jelly body how much Ethiopian opal is what's called hydrophane and hydro-
phane, hydrophane opal is an absorbent opal that easily loses or gains water in
when it's in contact either with water or even with the air hydrophane opal
tends to be unstable because having water entering and leaving the structure
of the opal will cause it to endure a lot of stress and that can cause
cracking so that's something just to watch out
for with a lot of Ethiopian opal absorbent or hydrophane opal is found in
many places in the world but Ethiopian opal is a bit of a classic for it
Madagascar two pieces of potch from Madagascar just with different body
colors and body tones this one was labeled papaya opal just because of its
color it's got a yellowish color and here's a piece of quite common opal or
pot with a little tendency towards translucency on the edge so they're from
Madagascar Tanzania we also have this orangey material it's not unlike orange
toned opal from many other places again these are from these are formed in in
the rock that has been deposited through volcanic processes rather than a
sedimentary rocks that Australia's best known opal fields are located in so
that's one piece from Tanzania but wait there's more there's this greenish
yellow another piece of Tanzanian Potch with a very different body hue or color
white potch from Tanzania again this one's got the sort of a core that has an
element of translucency and then a really opaque almost chalky white edge
to it and purple some poiple it's a sort of a lavender colored common opal
potch from Tanzania and sticking with the potch story these are from Turkey so this
is dendritic common opal from Turkey so these little feather or fern-like
inclusions are called dendrites this white opal with dendritic
inclusions is found in a number of places this is Turkish it's also found
in Western Australia and probably other locations common opal is surprisingly
common precious opal is very rare you may have noticed that this tour of the
world did not include all of the world in particular
apart from Turkey we missed all of Europe which includes opal bearing
locations like the Czech Republic Hungary and Slovakia other locations we
didn't visit were Nicaragua Guatemala and Indonesia and several others and
what that means is that at some point we'll get to do this all over again and
I'm looking forward to that already this video was made with the support and
participation of the Australian Opal Centre in Lightning Ridge you should
visit Lightning Ridge and you should visit the Australian Opal Centre you
should also follow the Australian Opal Centre on Facebook they are building a
world-class Museum in the Australian outback dedicated to opal opalized
fossils and local mining heritage it's going to be awesome
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I usually try not to tell anyone what's coming up in future episodes because
then I'm kind of obligated to make sure they actually get published but here's a
quick hint of what will be here in the near future we have dinosaurs and
egg-laying mammals with Liz we have a science experiment with Graham involving
pottery kilns and things that really don't belong in pottery kilns we've got
the mathematics of terrible fashion with me and an important piece of Lightning
Ridge opal mining history and heritage with Barb
stay tuned it's going to be fun oh and thank you for watching