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Elise
Joined: 22 Dec 2009
Posts: 243
Location: New York State
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Posted: May 01, 2013 13:20 Post subject: Mineral specimen repair |
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Hi,
I would appreciate learning about mineral repair; if & when to do so (under what conditions). Maybe this could be a general thread related to repairs of all sorts. I am wondering what to do about specimens which, for whatever reason, have suffered damage over the decades. This one, which is part of a historical collection, succumbed to enthusiastic hardness tests sometime in the past, consequently there is very little left of the natural surface features on the crystal faces. The points are rounded as well - not sure if that was natural erosion or mineral drawer jiggling with something unfriendly. I don't intend to whip out my orbital sander for this one, but would enjoy (maybe that is not the right word) reading about techniques used in cases that would warrant repair and cases that one just leaves be.
Best wishes,
Elise
Description: |
Spinel crystals in matrix 50 x 50 x 40 mm (approx) |
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_________________ Elise Skalwold |
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GneissWare
Joined: 07 Mar 2008
Posts: 1287
Location: California
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Posted: May 01, 2013 14:05 Post subject: Re: Mineral specimen repair |
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There is not much an honorable dealer would do to "fix" this piece. About the best one could do is oil it to hide the scratches. Lots of Chinese (and other) fluorite is made to look more presentable this way. If this was not a historic piece and/or was for reference, not display, I would do nothing to hide its history. At this point, its marks of testing are part of its history.
In general, some specimens need to be repaired to be presentable. For example, many tourmaline specimens or Colorado amazonite specimens, which are in a cataclastic environment and are almost always broken. It seems fair to repair them, if it is properly labeled. There is an interesting video by Jon Voelter I ran across which describes the scope of work from repairs to reconstructions, which may be useful. It is at
https://www.youtube.com/watch?v=8gbZcSfkraQ
(link normalized by FMF)
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Jordi Fabre
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Joined: 07 Aug 2006
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Susan Robinson
Joined: 05 Aug 2010
Posts: 163
Location: Hancock, MI
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Posted: May 01, 2013 15:11 Post subject: Re: Mineral specimen repair |
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Your mineral specimen is from an old classic locality. Its label is historic, too, and I would make sure it was safely kept with the specimen by placing it in a transparent plastic envelope of conservation quality. I'm also interested in the initials on the label in the lower left corner - any idea whose collection the specimen was originally in?
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Elise
Joined: 22 Dec 2009
Posts: 243
Location: New York State
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Posted: May 01, 2013 15:53 Post subject: Re: Mineral specimen repair |
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Hi -
I should have indicated that it is for a display in a museum setting; not resale. The initials are for Benjamin Silliman, Jr. and the specimen is from the 1860-70s. It has had a lot of wear & tear, as has the original label. It is one of the very few original labels, most of which were probably discarded in the late 1800s in favor of a succession of newer labels. I wasn't intending to repair any such historic pieces, but it is representative of the kinds of damage I am running into on reference and non-historic specimens. As you said, this one has historic importance because of the locality, provenance and label. I had posted a couple times about labels, one here: https://www.mineral-forum.com/message-board/viewtopic.php?p=24293#24293 Sometimes I think they are the most interesting part!
Jordi - thank you for that link, I didn't see that thread before I started this one.
Cheers,
Elise
Susan Robinson wrote: | Your mineral specimen is from an old classic locality. Its label is historic, too, and I would make sure it was safely kept with the specimen by placing it in a transparent plastic envelope of conservation quality. I'm also interested in the initials on the label in the lower left corner - any idea whose collection the specimen was originally in? |
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trtlman
Joined: 28 Jun 2011
Posts: 172
Location: Washington
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Posted: May 01, 2013 17:02 Post subject: Re: Mineral specimen repair |
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I think the scratches are a wonderful testimony to the pieces history. I assume when it is displayed it will displayed with some kind of placard to give a brief statement of the pieces history? Or at the very least when and where it was found. What I am curious about though is why was this piece tested so often? Was it a study piece for a classroom or science lab? That would be good information to include in the placard or to give during tours of the museum.
Imagine throughout history how many hands that mineral must have pasted through and how many eager young students scratched at it's surface while learning about the Mohs Scale of Hardness. That mineral has taught so much to so many, it would be a shame to cover that up.
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Matt_Zukowski
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Joined: 10 Apr 2009
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Posted: May 01, 2013 22:23 Post subject: Re: Mineral specimen repair |
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One expert on mineral restoration that I know is Riva, who works with Sandor at Mile High Mineral Cleaning Lab in Colorado.
I have also heard that Federico Pezzotta runs a lab in Italy that does excellent restoration work.
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John Medici
Joined: 02 Mar 2011
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Posted: May 02, 2013 17:06 Post subject: Re: Mineral specimen repair |
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Nice old specimen and label. I would not do anything to the specimen. The spinels at Amity are in a calcite matrix, but acid cleaning will alter the spinel surface.
Description: |
spinel Amity, New York 5,8X4.0 cm (spinel group) The calcite has been dissolved from around the spinels with HCl. Specimen collected around 1970. |
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Elise
Joined: 22 Dec 2009
Posts: 243
Location: New York State
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Posted: May 02, 2013 19:43 Post subject: Re: Mineral specimen repair |
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Hi John,
That is neat to see another specimen from the same locality - thank you! The image below is probably a better example for my inquiry (I wasn't going to do anything to the spinel specimen; just an example of a multitude of injuries).
This specimen is the same one I had posted under the calcite thread https://www.mineral-forum.com/message-board/viewtopic.php?p=26918&highlight=#26918 but a different angle and lighting reveals the fragile nature of the crystal's tip which is ready to break off given a stiff breeze. If that happens, I would be tempted to put it back on with a bit of wax or tape discreetly on the backside to hold in it in position - it would be non-permanent and hopefully not earn me the wrath of someone in the future who would shake his/her fist at my tombstone!
Cheers,
Elise
Description: |
Calcite included with Copper Hancock, MI 10 x 8 x 5 cm |
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GneissWare
Joined: 07 Mar 2008
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Posted: May 02, 2013 21:17 Post subject: Re: Mineral specimen repair |
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You can use thin cyanoacrylate glue to just wick into the crack. From a standpoint of being reversible in the future, a soaking in acetone will remove it without affecting the mineral. This is more a process of stabilizing not repair, as the tip is still in place. The goal is for it to remain so. As in all of these efforts, it needs to be labeled as stabilized.
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Jordi Fabre
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Posted: May 03, 2013 01:54 Post subject: Re: Mineral specimen repair |
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John Medici wrote: | Nice old specimen and label. I would not do anything to the specimen. The spinels at Amity are in a calcite matrix, but acid cleaning will alter the spinel surface. |
More interesting similar finds in the New York State here: New find of minerals from New York
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Elise
Joined: 22 Dec 2009
Posts: 243
Location: New York State
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Posted: May 03, 2013 12:40 Post subject: Re: Mineral specimen repair |
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Hi - Scribbling all this into my copy of Howie's manual. Here is another specimen which is in fairly good shape save a few tiny scratches on the wulfenites and one broken off crystal; mostly abrasions on the matrix. There are multiple tags which will stay on, but I was interested in Rock's "Life Saver" glued-on labels with name, locality and number. https://www.mindat.org/article.php/1263/Making+Labels+for+Mineral+Specimens
150 +/- years, some specimens have multiple labels, but documentation has disappeared, others have a separate label, but are not labeled on the specimen itself, so are in danger of being separated. Unlike others, this particular specimen has a good separate label with quite a bit of information, matching a painted-on #, though nothing matches the taped on #36 (obviously not the #36 of an old accession book). If the paper label gets separated from it in the future, there would be no way to match it easily - the problem with many specimens. Any thoughts on "life-savers" ? I don't want to add insult to injury (this method involves white glue and clear nailpolish)
Elise
GneissWare wrote: | You can use thin cyanoacrylate glue to just wick into the crack. From a standpoint of being reversible in the future, a soaking in acetone will remove it without affecting the mineral. This is more a process of stabilizing not repair, as the tip is still in place. The goal is for it to remain so. As in all of these efforts, it needs to be labeled as stabilized. |
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Wulfenite crystals Melissa Mine, Yuma, Co., Arizonia approx. 100 x 90 x 25 mm |
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Mineral accessions book 1897 |
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GneissWare
Joined: 07 Mar 2008
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Posted: May 03, 2013 14:30 Post subject: Re: Mineral specimen repair |
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I have conflicting views on extensive labels such as those Rock uses for normal collections, but see the value particularly in a study/museum environment. At the least, putting a label with locality info would be best.
As for using white glue, some specimens are water soluble so if you want to remove a white-glue-affixed label in the future, it could be an issue. Most minerals are not soluble in acetone. So affixing a label with the gel variety of cyanoacrylate glue, and using nail polish over the top is very reversible.
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Elise
Joined: 22 Dec 2009
Posts: 243
Location: New York State
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Posted: May 29, 2013 10:48 Post subject: Re: Mineral specimen repair |
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This is the same specimen I posted in the Calcite thread https://www.mineral-forum.com/message-board/viewtopic.php?p=31740#31740 but it shows the other side, which is actually the better side. The specimen is in poor shape, crumbling and abraded - and as with many specimens I am dealing with, the painted-on label is right smack on the best face of the nicest crystal! Grrrr. It probably is better left as-is and to focus on the problems of marcasite.
Description: |
Calcite on Marcasite Marsden's Diggings, Galena, Illinois 75 x 40 x 35 mm |
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lluis
Joined: 17 Nov 2006
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Posted: May 29, 2013 14:17 Post subject: Re: Mineral specimen repair |
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Hi, Elise
If you think that better side is what have the painted label, clean it, and place in the opposite.
Nevertheless, I would let it as is: age is a premium.... :-)
Stabilizing marcasite is another thing, and not that easy. It is just to have a place where humidity is low, very low. Maybe in a box with a dehydratant, if you have not such room (some have a color indicator, that says you when a change should be done...)
Nice pieces, besides
Lluís
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supertxango
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