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Quartz, Japan

Posted by Rock Currier  
avatar Quartz, Japan
March 24, 2009 07:26PM
©


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Click here to view Best Minerals Quartz and here for Best Minerals A to Z and here for Fast Navigation of 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?


Quartz
SiO2 trigonal

Here will go a good picture of a quartz specimen from Japan and general remarks about the quartz from this country.


Here are some url's to some of the better quartz specimens here on mindat that can be considered for inclusion in the article. These, in mosc cases are just for temporairy use untill we can get images of the much better specimens that are almost certainly out there. We should also consider that there are probably localities out there with fine specimens that are not even mentioned on mindat. Also in some instances there are sometimes pictures on mindat, of specimens from a locality, but they were so ratty that I did not include them here, but there may also be relly good specimens from there that we should talk about in this article.

(Localities ordered here alphabetically by prefecture.)


Quartz
Japan
Ogoya mine, Komatsu city, Ishikawa Prefecture, Chubu Region, Honshu Island, Japan
[www.mindat.org]

Rough amethystine crystals to 7cm, sometimes coated with crusts of purplish violet-brown-colored pyromorphite crystals (the quartz-pyromorphite colour similarity being presumably a mere coincidence!), in quartz veins filling fractures in rhyolite at the Ogoya copper-lead-zinc mine.


Quartz
Japan
Narushima Island, Nagasaki Prefecture, Kyushu Island, Japan
[www.mindat.org]
[www.mindat.org]

In recent years, “Suishohdake” on Narushima island has been a prolific producer of transparent colorless Japan-law twins (often incorrectly labelled “type locality” Japan twins at mineral shows outside Japan). A high percentage of the quartz crystals here are twinned (single crystals uncommon), mostly in square thin tabular habits around 1 cm, uncommonly to 3cm, of the “closed” twin variety, generally quite flattened, and additionally twinned according to the Dauphine or Brazil laws, as demonstrated by natural surface etch pits. Usually seen in collections as loose twins without matrix, rarely on matrix and as interlocking groups of up to six twins. A few contain pyrite crystal inclusions, or limonitized pyrite crystals on their surface. Formed in cavities in a network of quartz veinlets filling fissures in a friable Tertiary sandstone. The Naru village government has now prohibited collecting here because of the bothersome amount of sand being spread around the landscape and onto the road by overzealous collectors.


Quartz
Japan
Obira mine, Ono-gun, Oita prefecture, Kyushu Island, Japan
[www.mindat.org]

Double-terminated quartz xls are associated with acicular schorl sheaves in polymetallic hydrothermal veins in the Sensuji section of the Obira mine. In the Kohmori adit at this mine, clear quartz crystals to 8cm contain numerous spherical inclusions of light greenish chlorite (sometimes mistakenly alleged to be “cookeite”) to 4mm, apparently “floating” at different levels, together with phantoms of acicular white tremolite. Such specimens are popular with Japanese collectors and are affectionately known as “marimo” quartz, after a species of algae that forms floating spheres. White tremolite fiber inclusions in Kohmori adit quartz are sometimes grouped into parallel bundles, and the quartz crystals themselves can be heavily etched, giving the surface a "snake-skin" appearance and destroying the terminations. Obira mine quartz is generally colorless transparent, often associated with axinite or datolite; some quartz xls had their growth interrupted by thin plates of epitactic calcite (similar to the well-known specimens from Dalnegorsk in Russia). Japan-law twins also occur here, very flattened (much thinner than the better-known ones from Narushima island in Nagasaki). Green quartz crystals, colored by large amounts of green (presumably iron-bearing) inclusions, are associated with axinite at the Obira’s Hajikami adit. The crystals are translucent to opaque, taper gradually, losing the distinction between prism and pyramid faces, and turn yellow or brownish on long exposure.


Quartz
Japan
Ashio mine, Ashio, Tochigi Prefecture, Kanto region, Honshu Island, Japan
[www.mindat.org]


Quartz
Japan
Yamanashi Prefecture, Chubu Region, Honshu Island, Japan
[www.mindat.org]
[www.mindat.org]
[www.mindat.org]
[www.mindat.org]
[www.mindat.org]

The granodiorite vugs of the Kimpuu-zan (or Kinpusan) district were well-known since ancient times for their beautiful colorless “rock crystals” of symmetrical hexagonal cross section. These were used for ornaments, hanko (signature seals) and lenses, which industry lead to nearby Kohfu city becoming Japan's main gem cutting center (Japan's equivalent of Idar Oberstein). (Antique quartz ornaments and local quartz crystals collected in ancient times are displayed at Yamanashi University's quartz museum.) There are numerous quartz localities in this district, and for old specimens labelled “Kai” (the old provincial name for Yamanashi), “Kinpuzan” or “Otome mine” it may be difficult or impossible to determine the exact procedence. (WARNING: The quartz crystals sold nowadays at tourist shops in Kohfu city are almost all imported from Brazil!) Several localities are often lumped together under the name “Otome mine”: The original “Japan-law twins”, i.e. the “type locality” for this twin law, were from the Otomezaka deposit here, where they were relatively prolific in cavities in pegmatitic pneumatolytic quartz veins with topaz, tourmaline, feldspar, apatite, molybdenite, wolframite, chalcopyrite, sphalerite and galena, in granite. Rarely also in pegmatitic quartz without associated minerals. (Although similar twinning had been observed in quartz from Japan in 1870, and earlier yet from France in 1829, the Otome specimens reached Europe in 1895 so abundantly that Goldschmidt named the twin law for them in 1905. In Japan itself this twin law was at that time more modestly referred to as “twinning on inclined axes” or “twinned on the P2 face”.) These Japan-law twins can reach 45cm across (Wada collection), are quite flattened (eg: a 7cm wide xl can be less than 1cm thick, although the ratio is more commonly 1:3 or 1:4.), and possess well-developed trapezohedral (tetartohedral) faces allowing easy distinction of right- and left-handed crystals. Each of the individuals in the twin can also be twinned by the dauphine and/or brazil laws. Good transparent non-twinned pyramidal “rock crystals” are also abundant here, generally smaller than the japan-law twins, and are likewise sometimes “flattened”. Limonite coats the crystals and hides the innumerable etch figures in their faces. Specimens from Samusawa are similar to those from Otomezaka. Japan-law twins were most abundant at the Kurasawa deposit in pegmatitic quartz veins in granite, and the quartz is rich in several rare scalenohedral faces in addition to the normal rhombohedral ones. Crystal faces exhibit abundant tiny etch figures after their characteristic coating of limonite or “wad” is cleaned off. Also here, transparent prismatic quartz, often containing inclusions of unidentified greenish-grey to pale yellow acicular material, microscopic liquid bubbles, yellowish white chalcopyrite lamellae, minor epidote and chloritic material. This deposit was originally worked for scheelite and wolframite, but later mainly for its quartz crystals. Colorless to milky white prismatic xls occur in druses in granitic pegmatite at Suishoh-tohge, in Kurobera, including some transparent crystals to over 7cm bearing green chlorite phantoms, and superbly aesthetic “closed” Japan-twins to 6cm (National Science Museum); and, elsewhere here in Kohfu city, strange thin, bent xls to 9cm long, and magnificent scepter quartz xls to 8cm. Mukaiyama quartz crystals, normal hexagonal prisms, rarely with etch figures, commonly hold inclusions of epidote, and chloritic and asbestiform silicates, less commonly as internally clean, colorless crystals. Included quartz occasionally also from Masutomi. Simple colorless transparent prismatic xls were abundant from cavities in granite pegmatite at Hachiman. The prisms show a triangular cross section, terminated by a trigonal pyramid, due to exaggerated development of one set of rhombohedral faces; they generally are tapered toward the end, sometimes with gentle swellings. Usually with irregular striations, not quite parallel; more rarely finely striated and with abundant etch figures. May be colored greenish grey by minute acicular pyroxene inclusions. (True smoky quartz is rare in Yamanashi). Chloritic inclusions may form up to five concentric phantoms parallel to the pyramid faces. Japan-law twins were occasionally found in cavities in granite here, and the presence of chloritic phantoms distinguishes them from specimens from other japan-twin localities. Crystals from Gojohgoshaku are similar to those from Hachiman. (Japan-twins reported from miarolytic cavities in granite at "Obi", may well have been from Hachiman or Gojohgoshaku.) Druses in granite pegmatite at Takemori prolifically produced (until the site was recently closed to collecting) colorless transparent columnar crystals rich in inclusions, especially brown acicular dravite (such specimens being known to Japanese collectors as “kusa iri suisyou” = “grass within quartz”), green spheroidal chlorite, black anatase, minute scales of muscovite, epidote, rare monazite and red brookite, and even, rarely, up to 1cm inclusions of native sulfur! Chloritic material forms phantoms here. Unusual regular micropegmatitic intergrowths (simultaneous crystallization) of quartz with sekaninaite were found in the Sasago pegmatite (56.2 volume% quartz, 43.8% sekaninaite) and the Dohshi pegmatite (57.2% quartz, 42.8% sekaninaite).
Some general comments on quartz from the Kinpuuzan/Otome mine district: The largest recorded crystal from this district measured 1 m long, 30 cm wide, weight 130 kg. Corroded crystals are common, with triangular etch figures on faces and furrows along the edges. In extreme cases, innumerable furrows parallel to the edges can result in crystals so rounded that they resemble cylinders terminated by a cone (eg: in granitic pegmatite at Kamigane). Bent crystals and scepters are also known. Fluid inclusions are very common, sometimes macroscopic, either irregularly distributed, or parallel to a face as “phantoms”. In addition to the inclusions previously mentioned, there have been finds of quartz with inclusions of green filiform epidote, white irregular or stellate mica, pyrite crystals, acicular stibnite (Zodac collection?). Minerals associated with quartz in the veins and pegmatites include feldspars, mica, tourmaline, garnet, scheelite, ferberite (as pseudomorphs after scheelite), epidote, pyrite, chalcopyrite, magnetite, arsenopyrite, apatite. The northern part of this district (i.e. the northern slopes of Mt. Kinpuu) are across the border in Nagano prefecture (qv).



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

Rock Currier
Crystals not pistols.



Edited 9 time(s). Last edit at 12/29/2012 07:55PM by Rock Currier.
Re: Quartz, Japan
March 31, 2009 10:11PM
Kofu City, Yamanashi prefecture, Chubu region, Honshu Island, Japan

[www.mindat.org]
This is not a Japan Law quartz, just a faden quartz.

Which is still interesting, as a faden quartz indicates strain induced pockets that gradually open
in a somewhat malleable host rock.

Amir
avatar Re: Quartz, Japan
April 01, 2009 08:23AM
Amir,
Did someone say it was a Japan law twin? The caption on the image seem to correctly described as a faden type quartz.

Rock Currier
Crystals not pistols.
Re: Quartz, Japan
April 01, 2009 07:51PM
You are right.
My mistake.
I must have hallucinated the word "twins".
Re: Quartz, Japan
April 01, 2009 09:29PM
    
Rock,

Looks like we have two groups both claiming the original or "type" locality for "japan Law" twin specimens. One states "These original Japanese quartzes from which Japan law twinning was described initially" and the other "specimen of three twinned crystals of colorless quartz from the type locality for the Japan-law twin crystal habit".

hKofu City, Yamanashi prefecture, Chubu region, Honshu Island, Japan
[www.mindat.org]

Narushima Island, Nagasaki Prefecture, Kyushu Island, Japan
[www.mindat.org]


Do you or anyone else know the actual type locality? Perhaps Alfredo can help us??

Cheers,
Ian
Re: Quartz, Japan
April 01, 2009 10:24PM
The Otome mines on Kinpusan mt in Kohfu city are the locality for which Goldschmidt named Japan-law twinning. A large number of twins came from there in the late 1800s.

The other place, Narushima in Nagasaki prefecture, is NOT the "type locality" for the twins, although it did produce a lot of Japan twins in the late 20th century.

Technically, that type of twinning was first observed at La Gardette, France, about 70 years before the Kohfu pieces came out. But Goldschmitt apparently preferred abundance to chronology!

Cheers,
Alfredo
Re: Quartz, Japan
April 01, 2009 11:03PM
To add to the confusion - once more :D

The name for La Gardette a.k.a. Japan Law twins initially used by Descloizeaux in 1858 was
"macle du Dauphiné" or more exactly "macle du la-Gardette-en-Dauphiné".
(found in Friedlaender, 1951).

Which is very different from what we call Dauphiné Law twins today.

Amir
avatar Re: Quartz, Japan
April 02, 2009 02:16AM
Confusion is good. It makes people try and think clearly. I have confidence that Alfredo will sort it out and write it up all nicely to everyones satisfaction.

Rock Currier
Crystals not pistols.
Re: Quartz, Japan
April 02, 2009 02:43AM
But Rock, All I know is the geology and a smattering of the history and, occasionally, how big they get. For each significant occurence, I might be able to answer 3 or 4 of your 10 essential questions! There would be LARGE gaps for other people to fill in. Amir knows more about quartz than anyone in the world (except Si Frazier winking smiley)
avatar Re: Quartz, Japan
April 02, 2009 04:15PM
Yes Alfredo,
We are all pretty ignorant about most of the stuff in these articles aren't we? As knowledgeable as we think we may be, others always know things we don't. Our job is to add what we know and to create the framework where all these people who know more than we do can add their knowledge. Just the fact that there is a more or less organized place to put it brings people willing to help. Have you noticed? Right now there is hardly anything in Best Minerals, just a few demonstration articles which of which a few are a bit more mature than the rest. Imagine the flood of contributions there would be if we had several hundred or a thousand articles under construction. I look at all the new stuff in the IMA list, and I don't think we are even keeping up with the new stuff that is being described. But if we can get 50 or 100 people working on this, we may see some measurable progress. I am starting to believe, as important as descriptive text we generate may be, that in the long run it is going to be the pictures that will draw most people to this project. Everyone wants to know what the best ones look like and if they have a candidate for the best they would like to see it recognized as such. When they come for the pictures we can use those to rub their noses in more general and detailed knowledge about minerals.

We also need someone to go into the bulletin board archives and select out all the choice bits of information about many minerals and to put it into the thread for those minerals so that when someone is writing about them, they will have more information to draw upon and know better to contact about asking more questions.

Rock Currier
Crystals not pistols.



Edited 1 time(s). Last edit at 04/02/2009 07:05PM by Rock Currier.
Re: Quartz, Japan
April 03, 2009 02:24PM
I added some notes on various localities, under the Mindat photos Rock had put in his original post here. Rearranged the localities in alphabetical order by prefecture. For any errors, please blame the guy whose name is at the end of the descriptions winking smiley)
Re: Quartz, Japan
April 03, 2009 08:47PM
Great work, Alfredo!
avatar Re: Quartz, Japan
April 03, 2009 09:15PM
But Alfredo, We would much rather blame you! I have rewritten the introductory remarks for the Best Minerals section including a new section on the format we are currently using and advice to authors. If you have time read over the relevant sections and get back to me with your corrections, suggestions and comments.

Rock Currier
Crystals not pistols.
avatar Re: Quartz, Japan
July 27, 2010 01:17AM
    
Otome mine (Mitake mine; Kurasawa mine; Otomezaka mine), Kinpuzan district, Yamanashi prefecture, Chubu region, Honshu Island, Japan

www.mindat.org

A transparent Japan Law twin.
avatar Re: Quartz, Japan
July 27, 2010 01:33AM
AM, Definitely a candidate for inclusion in the article. Can you tell us something about the mine and how abundant such twins were and or how big they got from that locality?

Rock Currier
Crystals not pistols.
avatar Re: Quartz, Japan
July 27, 2010 01:48AM
    
Rock,

I do not have any detailed information regarding the locality or the quartz specimens found at the mine. Sorry. I did find a reference to a twin specimen from the Otome Mine that was 20 cm in height. It is on the cover of the book titled "The Mineral Species Of Japan" by Satoshi Matsubara.

AM



Edited 1 time(s). Last edit at 07/27/2010 01:55AM by AM Mizunaka.
avatar Re: Quartz, Japan
February 21, 2011 06:58AM
    
A couple more for consideration.

Suishoh-tohge (Suishotoge), Kurobira (Kurobera), Otome mine (Mitake mine), Kofu City, Kinpuzan district, Yamanashi Prefecture, Chubu Region, Honshu Island, Japan

www.mindat.org
www.mindat.org

The only information I got from the dealer was that this find was from a small pocket found in 2010/2011.
avatar Re: Quartz, Japan
February 21, 2011 08:34AM
AM,
Both are worthy suggestions and I am sure that when someone volunteers to write the Best Minerals, Quartz, Japan article that they will most likely be included.

Rock Currier
Crystals not pistols.
Re: Quartz, Japan
April 09, 2011 10:33AM
[www.mindat.org]

Very nice shot!
avatar Re: Quartz, Japan
April 10, 2011 09:28AM
Amir,
When someone gets around to seriously working on the Best Minerals, Quartz, Japan, the image you point out above will almost certainly be included. Why don't you take a crack at writing the article.

Rock

Rock Currier
Crystals not pistols.
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