FMF - Friends of Minerals Forum, discussion and message board

[Mark Ost]

Danke. I will look at the facebook page. My father was a fine painter though I have no pretensions to artistic talent. In an age of photography, painting seems like a refuge of old world skill. I like that idea. The only expression of mineral art is my using natural woods to mount my minerals. I see the point of the acrylic bases but I feel that natural objects are best surrounded by natural materials. They can be matched nicely. I need to post a picture of an adamite that I mounted on a piece of birds eye maple that had a bad spot that most wood workers would have cut out. I thought it added interest. No crystal is perfect so why exclude a spot on wood? Not only is the mineral fluorescent but the piece of mesquite wood that supports it is also fluorescent; as many woods also fluoresce. I'll post it tomorrow. In my microscope pictures I try to capture colorful spots that would go unnoticed by casual observation since they are small.

[Schwertner]

Thank you for answering, Mr. Ost.
I like the idea, to put minerals on wood. I have none on plastic. Some of my specimens are in an former aquarium put on fine quartz-sand. I feel sorry for the minerals that are removed from their ground, they were grown upon, they look like amputated.
So looking foreward to see your photo ..

[Mark Ost]

Thank you very much.You gave me a great idea (since I have never has on original thought in my life!). I often use glass, not as a completely enclosing case, as an accent to the mount but your aquarium idea has a lot of merit. Next mineral goes on wood with four sided glass open at the top and sand in the bottom for the mineral to rest in. No tack or adhesive required! I like this thought a lot. I'll let you know how it turns out. If they come already on acrylic I could bury the base so it looks like it is resting on the surface. Well drilling sand should work nicely, very clean and nice. They won't miss a little sand!

Great idea. Thanks again

[Mark Ost]

Here is the Birds eye Maple I spoke of. It had a bad spot but I thought it added to the organic look of the Adamite. The piece of wood that supports the sample is mesquite from a bag of wood chips for grilling bought from a chain store in the barbecue department!. The wood actually is nice and the yellow fluoresces along with the Adamite.

[Mark Ost]

Here is the glass container/display for the Tanzanite that I just posted under my collection. The idea came from Miss Schwertner. The Tanzanite sits in black sand and is propped against black Basalt. There are black stream pebbles and one white stream pebble for contrast. Some of the pictures were with the top light removed to show the bed clearly. Thanks for the fine idea and inspiration.

[cascaillou]

acid-sensitive minerals (carbonates, sulfides...) should not be stored in furnitures made of highly acidic woods (that is to say woods which have a pH under 5).

Here's a link which features a table of woods pH (it's at the end of the document):
https://preservart.ccq.mcccf.gouv.qc.ca/documents/bois_fr.pdf
(link normalized by FMF)

it is generally advised to avoid woods which have a pH under 5, although some sources consider pH 4.5 to 5 to be moderately acidic and thus acceptable.

[Mark Ost]

Thanks very much for the advise on wood. I will read the list. I wonder if the wood is sealed with oils or poly and serve as bases only, thus keeping the mineral exposed to air and isolated from the wood by the mounting material what the effect is. Currently the minerals and mounts are stored in metallic cabinets well ventilated, not in wooden cases. But let me read up. Just got back from Franklin last night so need to catch up.

[Mark Ost]

I went through the wood list and the species that I commonly use were not included, which is no surprise as many are exotic hardwoods. Thanks for the list and I will try to get through the French text of the article. Most seem in the 4 to 6 pH range. I would not lose sleep in the 6 pH or maybe in the 5. Below five might get my attention though.

[cascaillou]

Let me translate for you the part of the document about woods acidity:

All woods contain acidic compounds and release them both in salts form (non volatile) and in free form which is volatile. With time, the quantity of released volatile acids decreases but it never stops. Highly acidic woods should be avoided when air acidity is a risk for the stored objects, and if so it is generally advised to avoid woods with pH below 5

[Mark Ost]

Thanks for the translation. I will try to pin down the characteristics of the woods I use. There is an analogy here in fine optics in that you never put fine optics around concrete as the off gassing can attack the optical coatings used today. I must say museums always seem to use inert materials such as glass cases with minimal wood it seems. All my collection is 99% open air so hopefully if the bases do off gas the concentrations should be so low as to not affect the minerals, but I will keep an eye on them. Thanks for the input. Lets see what happens over time. I hope it does not affect them as a nice base is a visual treat and does enhance the presentation I think as long as it does not overwhelm the piece which is the focus. The wood bases also take up more room so require a bit more display space. I fear my French is far less than should be. Take Care. Mark

[Mark Ost]

Actually this raises an interesting historical question to our conservators and historians.

Prior to the invention of petro chemicals and plastics, what did museums and collectors typically use to mount or present their collection? Even glass display cases have wooden storage drawers. Glass has been around for quite some time obviously but I think this might be interesting from a historical perspective. Thanks for any input.

[cascaillou]

indeed a showcase made of highly acidic wood (such as oak) is going to be problematic as it isn't well ventilated. Still there are quite a few woods which are non acidic or low acidity which can be used for building a showcase with no risk for specimens.

[Mark Ost]

This is a classic science experiment. I will get a piece of calcite (non collectable of course!) and place it on a piece of oak or perhaps a small quick oak box. Lets see what happens over time. This will be a long term experiment I suspect but it is easy to do and requires no effort after getting started! My kind of science!

[cascaillou]

to speed up the experiment:
use some young oak wood, not antique, and make sawdust out of it,
Then you need an airtight transparent glass jar with lid (such as a jam jar, well cleaned).
Fill a third of the jar with the sawdust, and humidify with a little bit of distilled water.
Add the calcite on top of the saw dust.
Tightly close the lid, and place the jar in a warm place in front of a window (direct sunlight).

In the meanwhile, proceed to the same experiment using a sligtly acidic wood (young alpine fir wood for instance), for comparison.

[vic rzonca]

Mounting specimens.