Displaying meteorites in a dry environment
Collecting meteorites comes with the responsibility of having
to protect them
against often harmful environmental conditions on
planet earth. Most meteorites just don't like
when living in a wet climate environment, this can result in having to
meteorites away, out of sight, in
airtight containers containing desiccant. As a collector who lives in a wet climate, I found myself in such a situation.
To be able to enjoy seeing at least some of my
having to retrieve them from storage first, and without exposing them to
moisture, I worked out the concept described
below. It makes use of a
glass dome, a specially made aluminium base, silica gel desiccant
impregnated with a
blue indicator that turns pink when moist, a glass disk (coaster) and
white Vaseline. All
ingredients for the concept, except the aluminium base
were bought as is. The base was specially designed and
machined for the
glass dome originally came with a wooden base. I first tried to
create a dry compartment using this wooden base. To seal the interface
between base and glass dome, I first considered oil, but discarded this
idea as too messy. Adhesive or silicone sealant would be too
permanent. Finally I decided to try white Vaseline.
little dish with silica gel was put underneath the Vaseline-sealed
dome... It did not work. The
wood turned out to be too permeable for water. The silica gel absorbed
water from the wood so fast, that it turned pink in only a day.
next test of the concept, I used the same configuration, but this time
with aluminium foil covering the wooden
base. One sheet of foil covered the flat central base, and followed the
internal contour of the groove. Although not
looking very presentable, it worked! The blue silica gel stayed blue
Time for the next step...
on the first experiments, I decided to design a base, to be
machined out of a solid block of aluminium.
to a groove to hold the white Vaseline and to insert the glass dome in,
base should have a cavity to hold the silica gel. The blue silica gel -
impregnated with dehydrated cobalt chloride as a
moisture indicator - should not be able to
contact a meteorite. Air should be able to pass freely though. It
should be possible to check the colour of the silica gel
having to open the display. Furthermore I wanted a meteorite
to rest on glass, so I wouldn't have to worry about galvanic corrosion.
The result can be seen in the sketch to the left.
|To open a PDF file containing a drawing including
measurements, click the sketch to the right.
fill the groove with white Vaseline in such a way that
closed the gap between glass and aluminium, I made use of the low
melting point of white Vaseline. It melts at a temperature well
the temperature of boiling water.
A safe way to melt the Vaseline is by floating a little bowl
containing Vaseline in boiling hot water.
(Note: Using an oven to melt the white Vaseline can be dangerous,
as Vaseline fumes are flammable!)
To support the flow of molten Vaseline in the groove, and to obtain
sufficient time to place the dome, the aluminium base was pre-heated in
hot water (and dried afterwards). The heat capacity of the aluminium
base was more than sufficient, to be able to fill the groove and put
the dome in place
Vaseline started to solidify.
the left, the final result is shown. I'm
curious how long the silica gel with stay blue, indicating a safe
environment for the fresh stony meteorite inside.
The test with the aluminium foil covered wooden base worked well for
six months, after which I ended the test. The final configuration
didn't show any change in colour of the silica gel since
being closed two months ago (September 2011).
I designed the cavity in the base to be large enough, to contain
sufficient silicagel, to dry the air inside the dome. It will not hold
sufficient desiccant to dry any unconditioned meteorite also. Therefor
the meteorite should be dried - in for instance an air tight box with
desiccant - before being put in the dome.
I have been thinking about some possible improvements. White milk glass
could be used instead of the clear glass as a base plate for
the stone. A stand could be added inside of the dome, to lift the
meteorite. The challenge would be to make it stable though. Also a
lower dome might improve the display.
In case you might want to give it a try yourself, please feel free to
copy and improve the design as desired.
I would appreciate
hearing about your experiences!: info@AsteroidChippings.com