Cleaning the crystals is as hard or harder than the
actual digging. This process is tedious, strenuous and time-consuming. Oxalic acid, muriatic acid and other chemicals are used.
It also reqiures lots of care and patience. Though, there are some people who prefer uncleaned crystals, most people prefer the crystals to be cleaned. I usually try to have at least one or two uncleaned crystals on my display so one can see what I start with.
Arkansas Crystals, when freshly mined are usually always covered in
clay with underlying mineral deposits, consisting of various manganese and iron compounds. To remove all of this, they
must be cleaned. The mineralization and clay vary from place to place
where the crystals are mined, so each batch requires a slightly different
cleaning technique. This is almost an art in itself. FOR THOSE OF YOU WITH JUST A FEW CRYSTALS TO CLEAN, INSTRUCTIONS ARE AT THE BOTTOM OF THIS PAGE. please scroll to the bottom of the following discussion.
The technique, which I have outlined below, is a general
technique, which works best with crystals from, say, the Sweet Surrender
Crystal Mine, because the mineralization on them from that location are the hardest to clean. When cleaning crystals from most other locations, I can eliminate the muriatic acid steps.
When I first get the crystals, I carefully lay them
out, one by one, on screen tables or pallets, so as to let the clay
dry. I then rinse the clay off, little by little, as it comes off
with a water hose. Then I pressure wash them. Of course, some need to be held down, (while wearing rubber gloves, so I do not cut my hand with the water) so they do not go flying off the table!
Then, with rubber gloves and boots, and a gas mask,
carefully put them in 'straight' Muriatic Acid, which I double-boil
over a wood fire in a bathtub. Since I live adjacent to the woods, I go and cut and gather the firewood myself. I use pine, mostly. The hotter it is, the better the acid works. This takes at least one day. Many need boiled more than once. I usuaully wait until the heat of the summer to use the muriatic acid process, as the natural heat saves a lot of work. It just requires time and patience. Then: again w/gloves, boots, and mask, carefully, out, rinse, air dry.
Then, power wash some more until the most of the yellow
tinge from the muriatic is gone. Sometimes I have to plunge them into
a solution of soda ash and water, or, battery acid, in a large tub to get the yellow
off. Then rinse and air dry when they come out.
Then into Oxalic Acid water in another tub which I
heat over a wood fire for at least 4 to 6 hours. (I use one pound
of oxalic acid for every two and a half gallons of water- half a 50 lb bag in a bathtub. Sometimes
I mix it strongerfor heavily coated material.) Let cool, (it is important to let the water cool, because the acid tends to stick to the crystals when they are hot when just removed from hot acid water)
Then carefully lay them out on screen tables or pallets, rinse and power wash again
and again to remove any residual acid, clay or mineralization. Then
power wash again. Final rinse. Air dry.
After all this, most of the crystals then get plunged into a solution of sulphuric acid(battery acid), and/or, more recently, a n 'H9' solution, to further remove any of the yellow staining from the previous two processes. They go in there for 2 to 24 hours.
When the time is up, they then go into another tub of fresh (sometimes running) water, to get the sulphuric acid and other residue off. Then they come out, are set out, rinsed with fresh water a few more times, and admired.
Whew! Then the selecting, wrapping and packing begins. Fitting all the crystals into boxes is like a 3-d jigsaw puzzle! For the larger clusters, I have a small Bobcat which does some of the lifting, and a cart on a tractor for moving them around.
Then the pieces in the puzzle get bigger, but the principle is still the same. I use chains and straps when lifting them and rubber mats when placing them in the van. Extreme caution is exercised during these procedures. They get packed in with rubber mats and blankets and boards, and a helper!
Then wrap, pack and load. OR.., start the process over
for all the re-dos.
***HEY, FOR ALL YOU FOLKS WITH 'JUST A COUPLE' THINGS TO CLEAN: You don't have to run around town, looking for Oxalic Acid. You can use "Bar Keeper's Friend", or "ZUD" cleansers.
These products have oxalic acid in them and will work just fine. Simply put the material to be cleaned in a container big enough to hold it and be covered with water. Add the cleanser product to it, usually a half to a whole can is plenty.
Use hot water and fill to over the height of the material being cleaned. Crock pots on low work well. So do 5 gallon pots on low on the stove. Keep 'em covered and do not breathe th fumes. Usually takes 5 hours or so. If doing it cold, give it a couple days or so, covered, in the hot Sun.
Though, not scientific, these processes will work 90% of the time. To reclean crystals that are already cleaned, but just dusty: A garden hose for the big ones, and for the smaller stuff, you can put them in your dishwasher. They come out 'virtually spotless!' For crystals already cleaned you can also put them in a solution with oxalic acid and water for a minute and they come out really nice and white again..