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lyaniq
Joined: 20 Jan 2022
Posts: 3
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Posted: Jan 21, 2022 00:27 Post subject: Quartz ID |
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Hi
Just wondering what the quartz on the right is. I thought citrine but having doubts. It’s got some grey marks in some areas that makes me think smoky.. The clear quartz on the left is for colour comparison. If I can, I’ll add more photos showing detail.
It’s what it looks like after sitting in hci for a week (it had iron deposits on it). The yellow spot in the middle hasn’t come off as I think the mark is inside.
Also, I don’t know where this crystal is from - could its form tell the location?
Thank you.
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Bob Harman
Joined: 06 Nov 2015
Posts: 765
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Posted: Jan 21, 2022 00:55 Post subject: Re: Quartz ID |
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It is unfortunate that you don't have a locality as Quartz like you show is sooooo common, it could be from many localities. It might help if you give the specimen measurements.
The example on the left looks to be ordinary cloudy quartz. The dominant crystal on the right is nicely transparent so some might call that specimen Quartz, var rock crystal.
I personally reserve calling "Quartz, var rock crystal" for those examples where the dominant crystal(s) are larger, very clear and transparent, and really stand out, so measurements matter to me.
Also, the appearance of the side crystals adjacent to the main crystal have some characteristics of the specimen being called "alligator" Quartz.
The small areas of yellow are more likely to be iron oxide staining as they vary in hue and are much more common than true citrine, but more photos might help.
A word of warning.....soaking many types of specimens in HCl (and other chemical cleaners) for lengthy time periods, often creates unwanted chemical color changes further detracting from the specimen appearance.
Bob
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lyaniq
Joined: 20 Jan 2022
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Posted: Jan 21, 2022 02:23 Post subject: Re: Quartz ID |
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Thank you!
It’s 10cm high, 7cm wide at the bottom and 8cm wide at the top. It’s bought in a New Zealand store but more than likely imported. In this photo some grey areas are visible.
I can only upload one photo at a time, it seems.
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lyaniq
Joined: 20 Jan 2022
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Posted: Jan 21, 2022 02:26 Post subject: Re: Quartz ID |
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Another photo
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Bob Harman
Joined: 06 Nov 2015
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Posted: Jan 21, 2022 03:06 Post subject: Re: Quartz ID |
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Nice full cabinet size example!
The dominant crystals are big enough for my definition of Quartz, var rock crystal.
The patchy yellowish areas, I still think are iron oxide stains.
Welcome to this forum. Bob
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Tobi
Site Admin
Joined: 07 Apr 2009
Posts: 4108
Location: Germany
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Posted: Jan 21, 2022 03:13 Post subject: Re: Quartz ID |
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Hi,
this is a nice specimen with the many smaller crystals around the large one, it reminds me of the "cactus" amethysts from South Africa, also I know similar forms of quartz from Itremo in Madagascar. But, as Bob said, finding the correct locality is nearly impossible when you have a quartz specimen that has no very special distinct feature (e.g. the "mango" inclusions from Cabiche/Colombia or the blue/green inclusions from Messina Mine/South Africa). Also, matrix rock may give a hint but this specimen has no matrix. I fear we won't find out :-(
Same about the colour: There are many factors that can influence the colour of quartz, it may be the influence of radiation, little fractures or another anomaly in the crystal lattice combined with how the crystal reflects light, a small amount of a certain element or inclusions of another mineral. I think this is not a sample of citrine, smoky quartz or "milky" quartz. I am an avid quartz collector and if this was my specimen, I would simply label it as quartz. I think labeling it rock crystal would also be ok because the crystals are mostly colourless and transparent. But in doubt just "quartz" :-)
Regards
Tobi
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James Catmur
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Joined: 14 Sep 2006
Posts: 1346
Location: Cambridge
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SteveB
Joined: 12 Oct 2015
Posts: 235
Location: Canberra
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Posted: Jan 21, 2022 04:08 Post subject: Re: Quartz ID |
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Quartz, just quartz. There are indications of possible start of citrine variant as well as smoky variant starting in parts. But those indications could be other mineral coatings in areas previously accessible to liquid. HCl isn’t a guarantee of cleaning everything especially deep within a specimen. Crystals don't start out as large optically clear museum grade specimens but undergo changes during growth as the solution concentration changes, as well as changes in temperature and pressure so in reality all we really get are specimens in a stage of growth. All that you can honestly say regarding labelling is its quartz, no variant names attached or "New Age" trendy names. Quartz crystal cluster. Label as that and be happy.
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