I’m wondering if anyone is familiar with dendritic Chrysoprase? I
have a piece I’m working on, but when I go to the web to do a
search, it doesn’t turn up.
Don’t know if that’s because it’s so rare or if no one pays any
attention. Any help on this would be welcome.
Derek Levin
I'm wondering if anyone is familiar with dendritic Chrysoprase? I have a piece I'm working on, but when I go to the web to do a search, it doesn't turn up. Don't know if that's because it's so rare or if no one pays any attention. Any help on this would be welcome.
Chrysoprase is simply a chalcedony, same as many other varieties,
except that it’s been colored green by traces of nickel, either as
oxide or silicate. Like other chalcedonies, it sometimes is found with
other inclusions, which can include dendrites. Dendrites are simply
inter grown inclusions of other minerals which happen to form a
distinctive pattern. It’s common in chalcedonies, since these
microcrystaline forms of quartz are relatively porous, allowing the
penetration of aqueous solutions which can contain other minerals. If
these minerals desposit out within the structure of the chalcedony,
then dendrites are one possible resulting structure. In the case of
chrysoprase, it’s usually prized the most when, like fine jade, it’s
as brightly colored as possible, as translucent as possible, and as
free of other inclusions as possible. But this doesn’t mean that
unusually attractive specimens with other types of visual appeal, such
as an interesting dendrite, are not also desirable. Such stones would
pretty much have to be evaluated on a piece by piece basis, much as
the increased value of quartz with tourmaline needles or rutile
needles in it, depends much on the appearance and appeal of those
inclusions. One of the neat things about quartz gems in general is
that there is a virtually endless amount of variety to be had.
Hope that helps.
Peter Rowe
I'm wondering if anyone is familiar with dendritic Chrysoprase? I have a piece I'm working on, but when I go to the web to do a search, it doesn't turn up. Don't know if that's because it's so rare or if no one pays any attention. Any help on this would be welcome. Derek Levin
Derek, All the chrysoprase rough I have worked with has dendrites.
Usually near the edge of the seam. Most are small and not very
interesting in shape so they usually get cut out. (commercial cutters
avoid them) However, sometimes there is one (some) that extend into
the body of the seam with a very nice shape. This is a gift from the
rock gods. Use it! cut a really cool (maybe even scenic) cab worthy
of a fine piece of art jewelry and make your friends and colleagues
green with envy. (groan!) Mark
Mark Thomas Ruby
SunSpirit Designs
Loveland, CO
970 669-7075
Check out Lapidary Journal February 2002 there is an article on
dedrites… Chrysoprase is a chalcedony and it does occur with
dendrites but I would imagine that the solid ones probably sell
better. There is a book mentioned in the article called Genstone and
Chemicals: How to Create Color and Inclusions. by Dr. Geprge W
Fischer. Pub. 1991. Lap journal can probably get you a copy of that
issue. A most interesting article. Moss Agate is actually Not an
agate at all but is a chalcedony with dendrites. hope this
helps. good luck.
Derek Generally, good quality bright green Chrysoprase, with no
inclusions of any kind, is considered to be the most desirable
material, not unlike bright green jade, or bright green emerald. No
inclusions and the brighter the better
However, inclusions in any material can be attractive and desirable.
It’s a matter of what percentage of inclusions, the patterns
involved and how the inclusions blend and balance the overall piece.
If it works it works and if it doesn’t, it just doesn’t…
From what I have personally seen, dendrites in Chrysoprase are not
rare, nor are they necessarily desirable. Not unless your specific
customers find them to be desirable that is…
Just my opinion
RnL
Derick - I would guess that as much as 35% of the several pounds I
have show some dendrites. Typically, I find that the dendritic
patterns radiate into the stone from the top/bottom of the layers.
Sometimes there are even open fissures, tree-root shaped, which are
filled with a clay mineral. Many folks prefer only deep "imperial"
green without any other color or patterning; as a result, most of
the dendritic edges get scrapped, or fed to the tumbler.
Jim Small
Small Wonders
HI Derek, I’m very familiar with dendritic chrysoprase but what is
it that you want to know? Chrysoprase is a member of the quartz
family, hardness around 7. Cutting and polishing dendritic
chrysoprase should be much the same as cutting and polishing
dendritic agate (though some of the milky, opaque material can be
more porous and softer). Ditto for setting it in jewelry. I imagine
the reason you can’t find a reference to it is that, even though the
dendritic variety is not that common, it is also not a separate
species.
Beth
I'm wondering if anyone is familiar with dendritic Chrysoprase?
Derek, I’ve just been cutting some, and it makes very attractive
finished stones. I don’t believe it’s abundant enough to find a
niche market on its own, but some chrysoprase seams have been
intergrown with what appears to be black manganese dendrites,
somewhat similar to those in Montana Agate. Most of my material is
rather pale green and the dendrites are grouped fairly close to the
edges of the slabs so careful cutting is necessary to show off the
dendrites and best green color effectively. There’s usually an
unattractive whitish mineral I haven’t yet identified that
penetrates some of the dendrites and I try to cut it away. I’m not
certain which Australian mine produces this particular type. I’ve
cut lots of the fine old Marlborough chrysoprase and haven’t
previously run into dendrites so I suspect it’s production from a
different location.
Rick Martin
MARTIN DESIGNS
About dendritic chrysoprase…Several of you have mentioned that
clear green chrysoprase is the standard of the industry and that
anything that has pattern is less apt to sell. Oddly enough, I have
always been dumbfounded by the fact that plain chrysoprase sells so
poorly whereas the ones that have dendrites or pattern sold well. I
suspect that the bold green of the clear material is somehow
perceived to be un-natural. I onder if anyone else has had a
silmilar experience ? Ron at Mills Gem, Los Osos, CA.
There uesed to be a chrysoprase from California that was milky light
green with dendrites. This material was cabbed for the dendrite
patterns. The material was not clear or translucent. It was softer
than gem grade material. The material did not yield a high polish
on all stones. Some were chalky. I always wondered if the
material were true chrysoprase. You may want to contact California
dealers or clubs. Steve Ramsdell
Derick. I have seen a lot of dendrites in chrysoprase. About 5
years ago at one of the desert shows in Arizona a man from Australia
had a 3/4 ton pickup full of rough chrysoprase. None of this was
the so called gem grade gel. What a variety of colors and patterns.
Unfortunately I found him after I had already spent most of my
cash. He would only take cash so I bought about 10 pounds from him.
This rock has many skin dendrites and a quite a variation in color.
He had boulders of chrysoprase weighing 50+ pounds that made my
mouth water. I have never seen any dendrites in chrysoprase that
extended all the way to the center of the rock. On the other hand I
have not seen many tons of the material either. If any exists like
the dendritic agates I would surely be interested. Any Australians
have a better view of dendrites in chrysoprase?
Gerry Galarneau
www.galarneausgems.com
See you in Las Vegas, G+LW20
31 May 2002
A couple of people have mentioned chrysoprase in combination with a
white, chalky mineral. I seem to recall that it’s magnesite, a white
mineral when in its pure form. When the magnesite and chrysoprase
blend together evenly, the result is often sold as lemon or citron
chrysoprase. I have also been told by reputable dealers that some
"lemon chrysoprase" is magnesite which has been colored by something
other than chrysoprase, while some does actually contain chrysoprase.
Beth
Thanks for all the responses. The reason I was asking about
dendritic chyrsoprase is that I did a search on the web and turned
up nothing. I mean nothing in several search engines. I was
wondering if the black was manganese which someone suggested it is.
The piece I’m working on is 77 carats and has great saturation of
green/blue. It is definitely Australian since I bought if off an
Aussie miner.
The dendrites were buried beneath a layer of the brown, what I
assume to be, ironstone matrix, since both this and boulder opal
come from Queensland. Frankly after all the cruddy prase I’ve
looked at over the years, I was surprised to see how clean this is,
especially with the black inclusions. People are always so
interested in the dendrites in agate. This particular piece was
also practically clean of the wonderful white crystal-lined vugs
that spoil so much prase.
I am however still mystified that no one on the internet has
recorded how very interesting and attractive a good piece of
dendritic prase can be. I used the black as the center of a pansy.
I’d love to find more that was clean except for the dendrites.
Thanks again for all the help.
Derek
Dear Beth, There are a couple of locations in California for the
magnesitic chrysoprase. In each case the magnesite may be floaing in
the chrysoprase or may be the dominant mineral Similar occrrences
in Australia bear a strong resemblance to the California material,
but the association is further complicated by the occaisional
admixture of Gaspeite. The material in which the magnesite floats in
a sea of green agate is phenomenal; it is very much like cumulous
clouds wafting in a greenish sky. It is one of my favorite materials
for designer cabs. If you would like to see some examples thereof
check out our booth at the California Federation show in July in
Placerville.
Ron at Mills Gem, Los Osos, CA.