Has anyone heard of mastodon ivory treated to look like turquoise? A
process developed by the Cistercians. Material in early French crowns
assumed to be turquoise is really heat treated mastodon Ivory. A
German curator at the Louve figured this out. Hmmm? Micky Roof
Micky - If the Cistercians made it, they were only copying a natural
substance. The original material is odontolite, which is fossil bone
or ivory which has been colored blue by the iron phosphate mineral
vivianite. I have a small piece, and have cut it. While my chunk is
a nice blue, the literature says it often comes from the ground a
blue-grey color which can be enhanced to brighter blues by careful
heat treating. Maybe this is what the Cistercians did.
Jim Small
Small Wonders
Has anyone heard of mastodon ivory treated to look like turquoise? A process developed by the Cistercians. Material in early French crowns assumed to be turquoise is really heat treated mastodon Ivory. A German curator at the Louve figured this out. Hmmm?
Micky, I have a necklace of 3 strands of 4-5 mm ivory beads which
are turquoise-colored. I got them several years ago from someone who
knew nothing about them, so I don’t know if they are mastodon or some
other kind of ivory, but the crosshatched grain is easily apparent.
I, too, have wondered about the coloring process. The beads appear
to be rather old.
Thais in Asheville
Has anyone heard of mastodon ivory treated to look like turquoise? A process developed by the Cistercians. Material in early French crowns assumed to be turquoise is really heat treated mastodon Ivory. A German curator at the Louve figured this out. Hmmm? Micky Roof
I wouldn’t want to contradict a curator, but in my experience
mastodon (or any ivory) responds poorly to heat: discoloring,
crazing and delaminating with progressively greater exposure. Are you
sure this was a heat process? Dyed ivory is common, and (cold)
immersion in a solution containing copper salts would likely produce
a turquoise-colored material. I’ve found naturally-occuring blue
areas in mastodon and mammoth ivory that was dug up in Alaskan gold
mines, probably caused by a similar process occuring over time.
Andrew Werby
www.unitedartworks.com
Andrew - You are absolutely correct! Odontolite is a true fossil, and
no longer ivory. That is the key to the entire issue; the blue
vivianite is part of the apatite group (fluoroapatite being a big
component of ivory, teeth and bones). Both June Culp Zeitner and
John Sinkankas mention the gentle heat treatment as a way of
"brightening" the blue of the material. In contrast, there is much
"blue" mastodon and mammoth ivory available which isn’t fossilized
at all - only preserved by glacial cold. This material responds
poorly to heating because it hasn’t had the mineral replacement
which characterizes fossilization.
When I originally saw odontolite written up, it was strictly as a
turquoise simulant. Mention was made that the simulant was
considerably rarer than the natural turquoise. My small chunk of
odontolite has a mid-western origin; Zeitner and Sinkankas both
mention the fossil beds of Kansas, Nebraska, and South Dakota as
sources, again distinguishing the material from the tundra preserved
true ivories. I ought to have included more detail on my first post.
Jim Small
Small Wonders
You are absolutely correct! Odontolite is a true fossil, and no longer ivory. That is the key to the entire issue; the blue vivianite is part of the apatite group (fluoroapatite being a big component of ivory, teeth and bones). Both June Culp Zeitner and John Sinkankas mention the gentle heat treatment as a way of "brightening" the blue of the material. In contrast, there is much "blue" mastodon and mammoth ivory available which isn't fossilized at all - only preserved by glacial cold. This material responds poorly to heating because it hasn't had the mineral replacement which characterizes fossilization.
Thanks for clearing that up, Jim. Sometimes one has to shoot ones
mouth (or keyboard) off in order for the truth to emerge… So
Odontolite is ivory that has been replaced by vivianite, a bluish
mineral? And it can be heat-treated, while that won’t work with
non-petrified material? I think I’ve got it now. How does one tell
the difference? Is there a simple test (short of heating it to see
what happens), or does it take elaborate equipment?]
I wonder where the European sources were. Is this something that’s
possible to purchase anywhere, or is it so rare as to be practically
unavailable?
Andrew Werby
www.unitedartworks.com
Andrew - From my limited experience the difference is very apparent;
all the “fossil” ivory which I have seen from dry land/warm climates
is very splintery, and most of it is quite oxidized. The one piece
of odontolite I have is obviously mineral in nature, and only shows
its history by carefully examining the grain texture. I have never
seen it intentionally for sale; the one piece I bought was part of a
larger lot of turquoise, and had been misidentified. If you want to
pursue a source, my best suggestion would be to check out
paleontological suppliers. Perhaps other Orchid members who are
familiar with the annual Tucson offerings have seen it for sale.
Good luck in finding some: until Micky mentioned it, I don’t think
I’ve seen it discussed on-line since I started participating in
forums in 1997.
Jim Small
Small Wonders
Hi: Living in the great northwest i have had the ability to purchase
mastadon ivory from estate sales, eskimo indians, and fisherman who
made their living in alaska. I, at one time in my life interviewed
for a job wnere they made odjects from ivory. I got upset when I saw
specimans with spearpoints embeded being destroyed. I asked why they
were not at least saving the object for study and the supervisor told
me not to ask questions, none to say the least i, did not get the
job!! I personally did not like seeing these things destroyed as who
knows the story they could have told. Personally I think they were
getting the ivory illegaly, making mastadon beads that were strung
and sold in New York. Otherwise i have seen much fossil stuff and it
is usually much as it appears in life although it is stained by
minerals thea are in the groundwater. I have seen fossil dinosaur
stuff but i do not believe that mastadon has been on the planet long
enuff to turn to rock… Ringman John Henry
I have seen fossil dinosaur stuff but i do not believe that mastadon has been on the planet long enuff to turn to rock....
Material need not have turned to stone to be correctly termed a
fossil. “Preserved from a past geologic age” is sufficient.
It is correct to call mastodon ivory a “fossil” or “fossil ivory”;
it is no t correct to call it “fossilized” which implies that its
basic nature/chemica l composition has been changed.
Dino bone, on the other hand is both a “fossil” and “fossilized,”
since the original material has been replaced by inorganic matter AD
“petrified” or turned to stone, so to speak.
Beth
yes indeed it is a fossil as geology terms apply, but again…i
believed the term fossilised refers to the mineralized replacement
of cell materials. you tell me? ringman