Mindat Logo
bannerbannerbannerbanner
Welcome!

Stichtite

Posted by Ralph Bottrill  
avatar Stichtite
April 12, 2009 01:23PM
Click here to view Best Minerals S and here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.


Can you help make this a better article? What good localities have we missed? Can you supply pictures of better specimens than those we show here? Can you give us more and better information about the specimens from these localities? Can you supply better geological or historical information on these localities?
Should the different species be treated in separate articles?



Stichtite
(Mg6Cr2(CO3)(OH)16.4H2O) rhombohedral
Stichtite in serpentine, Tunnel Hill, Dundas, 20cm across© R. Bottrill


Stichtite is an uncommon magnesium chromium hydroxycarbonate which belongs to the hydrotalcite group and forms a series with hydrotalcite, pyroaurite and woodallite. Barbertonite is a less common hexagonal polymorph that belongs to the sjögrenite group and may occur as intergrowths with some stichtite. Stichtite was known from Dundas since 1891 and was first recorded (albeit described incorrectly as “kammererite”, a chromian clinochlore) by Petterd (1896) after a specimen from there was exhibited at the Tasmanian Exhibition in Launceston in 1891 (Twelvetrees, 1914). It was later recognised as a new mineral by Petterd (1910), after chemical analysis by A.S. Wesley at the Mt Lyell mine, but Petterd died in 1910 before describing the mineral properly. It was formally described by Twelvetrees (1914) who sent material to Europe for more detailed analysis by several mineralogists and collated the various mineralogical data from Petterd (1914, description), Ward (1914, optics), Hezner (1914, chemistry) and Himmelbauer (1914, structure). It was named stichtite after Mr Robert Sticht, general manager of the Mt Lyell mines, and a world-renowned pioneering metallurgist and sponsor of Petterd’s first catalogue of minerals.

The original find and type locality was described by Twelvetrees (1914) as “the razorback crest of a ridge above the Adelaide silver-lead mine, Dundas”. This description corresponds well with the present workings on Stichtite Hill. A co-type sample is stored in the ENSM, Paris, France (Sutherland et al., 2000).


Locations
Australia
Tasmania, Macquarie Harbour, Birches Inlet, BHP prospect
Australian Journal of Mineralogy (2006) 12: 101-107

Tasmania, Zeehan District, Dundas mineral field, Adelaide Mine (Adelaide Pty Mine; Adelaide Proprietary Mine)
Anthony, J. W. et al. (1997): Handbook of Mineralogy, Vol. 3, 39

Tasmania, Zeehan District, Dundas mineral field, Bonanza Mine (Lucky Star Mine)
Australian Journal of Mineralogy (2006) 12: 93-99

Tasmania, Zeehan District, Dundas mineral field, Red Lead Mine
Bottrill & Baker (in prep) Catalogue of minerals of Tasmania

Tasmania
Zeehan District, Dundas mineral field, Stichtite Hill (TL)
© JSS
http://www.mindat.org/photo-72974.html
Australian Journal of Mineralogy (2006) 12: 101-107


Tasmania, Zeehan District, Dundas mineral field, West Comet Mine
Bottrill & Baker (in prep) Catalogue of minerals of Tasmania

Tasmania, Zeehan District, North Dundas, Nevada Ck
webmineral.com/specimens/PG2MS/047-11Small.jpg
Bottrill & Baker (in prep) Catalogue of minerals of Tasmania

Tasmania, Zeehan District, Dundas mineral field, Serpentine Hill, Tunnel Hill Quarry
© Greg Murray
http://www.mindat.org/photo-15438.html
Bottrill RS & Baker, WE (in prep) Catalogue of Minerals of Tasmania. Mineral Resources Tasmania

The five main stichtite deposits in Tasmania (Figure 1) are Serpentine Hill, Nevada Creek, West Comet, Stichtite Hill (probable type locality) and Birches Inlet (on Macquarie Harbour, about 100km south of Dundas). The Stichtite Hill area is presently being mined for stichtite and serpentine (mostly for carving and polishing: Bottrill and Brown, 2000; Figs. 2 & 3) and is one of the principal sources of stichtite specimens in the world. The lilac stichtite in a yellow-green to black serpentine matrix makes attractive specimens.
The stichtite deposits at Dundas are all hosted by generally massive serpentinite bodies, probably derived from altered chromite-rich dunites within mid-Cambrian ultramafic complexes, particularly the Dundas ultramafic complex (Brown, 1986; Burrett and Martin, 1989) These complexes are a series of thrust-emplaced, dismembered ophiolitic bodies along the Dundas Trough, which bisects western Tasmania. They were deformed and intruded by mineralised granites during the Devonian era (Brown 1986).The occurrences are erratic, both in size and distribution within the serpentinites, and some appear to be related to brecciation of the host serpentinite. The occurrences include zones with small spots of stichtite nucleated around chromite (Fig. 4), and zones with stichtite remobilised during deformation into coarser patches and irregular vein-like bodies (up to 20 cm across; Fig. 5). The latter style of occurrence is the main source of stichtite specimens for collectors.
Stichtite occurs as opaque to translucent, pale pink to lilac, orange (any photos of orange stichtite?), mauve or deep purple, fine-grained, massive to micaceous material with a waxy lustre. It commonly contains disseminated chromite-magnesiochromite grains (up to 1 cm diameter), which may be octahedral or occur in irregular to highly angular fragments. The stichtite is hosted in massive to schistose, pale to yellowish green, dark green or black serpentinite. The serpentinite contains mostly serpentine minerals and minor chlorite, talc, magnetite and haematite. The black serpentinite contains abundant fine-grained disseminated magnetite. The serpentines mostly comprises lizardite and/or clinochrysotile, but antigorite occurs in some schistose serpentinites. Asbestiform chrysotile is a rare associate of stichtite, but occurs in some nearby serpentinites.
Discrete macroscopic stichtite crystals are unknown, but in thin section it consists of fine-grained platy or micaceous to radiating fibrous aggregates of crystallites to 2 mm or more in size. It forms radiating aggregates around, and largely replacing, chromite and also part of the surrounding serpentine minerals. In some samples, stichtite is partly altered to a chromian clinochlore (“kammererite”. Stichtite may also occur in association with aragonite, talc, clinochlore, haematite and magnetite. Some stichtite is partly weathered to soft pink aggregates that can include mountkeithite, hydromagnesite, kaolinite or magnesite,

Australia
Western Australia, Wiluna Shire, Mount Keith, MKD5 nickel deposit

Nickel Mineralisation in Western Australia by R.J. Marston 1984.
Grguric, B.A., 2003: Minerals of the MKD5 nickel deposit, Mt Keith, Western Australia. Australian Journal of Mineralogy, 9, 55-71.


Morocco
Souss-Massa-Draâ Region, Ouarzazate Province,Tazenakht, Bou Azzer District

© 2005 M. Kampf
http://www.mindat.org/photo-34032.html
Favreau, G. and Dietrich, J. E. (2006). Die Mineralien von Bou Azzer. Lapis 31(7/8), 27-68

Dunite quarry, Greenhills, Southland, South Island, New Zealand
D. Coombs in Micro-Scope, August 1992
The thin purplish film is mainly stichtite. Its presence at this locality was confirmed by Professor Douglas Coombs..


Saranovskii Mine (Saranovskoe), Saranovskaya (Sarany) Village, Gorozavodskii area, Permskaya Oblast', Middle Urals, Urals Region, Russia
© Pavel M. Kartashov
http://www.mindat.org/photo-225379.html
Impregnation of fine-grained lilac stichtite colouring outer parts of calcite vein fragment. In difference from more abundant and very similar chromian chlorite (var. rhodochrome) this stichtite is completely soluble in acid together with calcite. Associating mineral is unidentified yellow clinohumite-like grains (arrowed). Specimen size is 8x4.5x4 cm. Collected in 1986.

Kaznakhtinskii massif, Ust'-Koksa district, Altai Republic (Gorno-Altayskaya Autonomous Oblast'), Western-Siberian Region, Russia
© Pavel M. Kartashov
http://www.mindat.org/photo-224901.html
11x7x1.8 cm segregation of almost pure granular purple-violet Stichtite. Small admixture of brownish serpentine present on outer parts of the specimen. Abundant rhombohedral holes are result of dissolution of crystals of magnesite. Diameter of the coin on daughter photo is 1,65 cm. Collected before 1989.


Consolidated Murchison Mine, Gravelotte, Murchison Range, Limpopo Province, South Africa
© 2005 M. Kampf
http://www.mindat.org/photo-34348.html


Kaapsche Hoop, Barberton District, Mpumalanga Province, South Africa
© 2002 John H. Betts
http://www.mindat.org/photo-5874.html
Minerals of South Africa
This is the type location for barbertonite, but there is some doubt about the actual existence of this polymorph of stichtite.


Stolzburg, Barberton District, Mpumalanga Province, South Africa
© Martins da Pedra
http://www.mindat.org/photo-69026.html
Minerals of South Africa

Kaapsehoop, Mpumalanga Province, South Africa
© Debbie Woolf
http://www.mindat.org/photo-187804.html
Minerals of South Africa

Refs

Bottrill, R.S., and Graham, I. (2006). Stichtite from western Tasmania. Australian Journal of Mineralogy. 12, 101-107
Bottrill, R. S., and Brown, G., 2000: Rare Australian Gemstones: Stichtite: Australian Gemmologist, 20, 391-393.

Petterd, W.F., 1914: Description of the mineral. In: Twelvetrees, W.H., (ed.), Stichtite: a new Tasmanian mineral. Tasmania Dept. Mines, Geological Survey Record, 2, 3-4.
Sutherland, F.L., Pogson, R.E., Birch, W.D., Henry, D.A., Pring, A., Bevan, A.W.R., Stalder, H.A. and Graham, I.T., 2000: Mineral species first described from Tasmania and their type specimens. Australian Journal of Mineralogy, 6(2), 104-128.
Twelevtrees, W.H., 1914: (ed.), Stichtite: a new Tasmanian mineral. Tasmania Dept. Mines, Geological Survey Record, 2, 11pp.
Bottrill, R.S. & Baker, W.E. (2008) A Catalogue of the Minerals of Tasmania. Bull. 73. Tasmanian Geological Survey

Ralph Bottrill 12/4/09



Click here to view Best Minerals S and here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.

Regards,
Ralph



Edited 7 time(s). Last edit at 03/26/2012 06:25PM by Rock Currier.
avatar Re: Stichtite
April 13, 2009 11:25PM
    
Hi, Ralph!
How is for you the specimen [www.mindat.org] ? ;)

Kind regards,
Pavel
avatar Re: Stichtite
April 14, 2009 10:51AM
Pavel
Nice specimen, thanks for this, I will add it to the article
Ralph

Regards,
Ralph
avatar Re: Stichtite
April 15, 2009 10:37PM
    
One more specimen and locality - [www.mindat.org] :)
avatar Re: Stichtite
April 16, 2009 12:42AM
Pavel
Another wondeful specimen, thanks. I have added it to the article. Any more information on these aoccurrences (how common, how large, etc.), would be most useful.
I am particularly interested in this last one as we are working on the parageneseis and formation of stichtite and this one is very different to any others I have seen (except a strange Czech ine which I doubt). We felt it generally has a low temperature origin (perhaps in brecciated zones on the seafloor) but if it contains clinohumite that suggests a high temperature skarn origin. Any info welcome
Ralph

Regards,
Ralph
avatar Re: Stichtite
April 16, 2009 01:11AM
    
Dear Ralph,
I haven't see larger or better specimens of stichtite from both these deposits. But this don't means nothing. I'd obtain both specimens quite easy, so they apparently aren't the best known on deposits. Local collectors may to have (should to have, I think) more better specimens.
What about clinohumite, I am only suppose that it may be some hydroxil-rich member of the group. Most silicates from the deposit are chromian and are colored in green (titanites, vesuvianites, garnets, pyroxenes) or pink (chlorites, amesite). This mineral is brownish-yellow, so it may be not silicate at all, but brookite or anataze. From other hand TiO2 polymorphs from these veins are usually well crystallized. But the mineral form rounded transparent grains very typical for olivine-like minerals in calciphires. It is necessary to analyze it for more sure. I may only to speak, that this vein is quite low temperature may be 50-100-150o C not more.
Pavel
avatar Re: Stichtite
April 16, 2009 05:03AM
Thanks Pavel
Interesting stuff, and I look forward to hearing more from you on theses specimens.
I still cannot find my box of grimaldiite, but I thought it may have represented deconmposed stichtite(?)
Ralph

Regards,
Ralph
Re: Stichtite
June 11, 2009 03:28PM
    
Hi Ralph

Some years ago I bought a nice piece of Stichtite which was labeled " Hobbs belt Metamorphics, Noddy Creek, Sorell, East- Tasmania" It's no doubt that it is Stichtite, but I fear that the locality is wrong. Can you please help?

Best regards

Øivind Thoresen
avatar Re: Stichtite
June 12, 2009 01:58PM
Hi Øivind
This label is all very confused. Stichtite occurs sporadically in a complex sheared belt of mafic and serpentinised ultramafic rocks cutting across the Sorell Peninsular, a very wild and isolated part of southwestern Tasmania. Sorell is in eastern Tasmania and has no known stichtite or serpentinite. The Hibbs belt was previously called the Hibbs Ultramafic belt, and later the Point Hibbs Mélange or simply Hibbs melange, while the Noddy Creek Volcanics is a nearby parallel belt of andesites and diorites of younger age. Most stichtite came from the a small prospect near Birches inlet in the Hibbs belt and I entered this location as:
"BHP prospect, Birches Inlet, Macquarie Harbour, Tasmania, Australia"

Regards,
Ralph
Re: Stichtite
June 29, 2009 01:12PM
    
Thank you Ralph!

I will soon put out a picture of the sample .

best regards

Øivind
moical
Re: Stichtite
November 23, 2010 11:13PM
My brother and I discovered a very wonderful deposit of stichtite on serpentine while hunting in Oregon, we have samples that would best many of the picture posted here... Would you like to see them.
avatar Re: Stichtite
November 24, 2010 03:07AM
Moicel,
I am sure that many people here on Mindat would like to see them. You may if you wish take some pictures of them and place them as an attachment to your thread posting. I would recommend that you post them on the Collecting form which is located in the How To section of the message board. We would prefer if you would register with Mindat using your real name and many of the people viewing the pictures will want to know what the locality is. For pictures of your material to appear here in a best minerals article we will require a good locality to go along with the picture. Keep in mind that the mindat message board is not a place to advertise things for sale.

Rock Currier
Crystals not pistols.
Author:

Your Email:


Subject:


Attachments:
  • Valid attachments: jpg, gif, png, pdf
  • No file can be larger than 1000 KB
  • 3 more file(s) can be attached to this message

Spam prevention:
Please, enter the code that you see below in the input field. This is for blocking bots that try to post this form automatically. If the code is hard to read, then just try to guess it right. If you enter the wrong code, a new image is created and you get another chance to enter it right.
CAPTCHA
Message:
Mineral and/or Locality  
Search Google  
Copyright © Jolyon Ralph and Ida Chau 1993-2014. Site Map. Locality, mineral & photograph data are the copyright of the individuals who submitted them. Site hosted & developed by Jolyon Ralph. Mindat.org is an online information resource dedicated to providing free mineralogical information to all. Mindat relies on the contributions of thousands of members and supporters. Mindat does not offer minerals for sale. If you would like to add information to improve the quality of our database, then click here to register.
Current server date and time: October 22, 2014 04:49:28
Mineral and Locality Search
Mineral:
and/or Locality:
Options
Fade toolbar when not in focusFix toolbar to bottom of page
Hide Social Media Links
Slideshow frame delay seconds