The Cleaning Process
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, and other oxides and minerals. 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, you can use Zud or BarKeeper's Friend Cleansers. 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 the Sweet Surrender Crystal Mine, because the mineralizations on them from that location are the hardest to clean. This is usually limonite and other ferro-manganese compounds. 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 that is how it comes off with a water hose. Then I pressure wash them, repeatedly, until I am satisfied that no more clay and mineralization can be washed off with just water. 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, boots, suit, and a gas mask, carefully put them in 'straight' Muriatic Acid, for several days to a month or more, depending on the mean outside temperature, and how old the acid is.
Then, in full PPE suit, out of the acid and rinse until the most of the yellow tinge from the muriatic is gone. Then, plunge them into a solution of IRON OUT and water, in a large tub to get the yellow off. Then rinse and air dry when they come out.
For Crystals from sandstone deposits: Rinse and pressure wash all the clay and debris off as much as possible. Then into Oxalic Acid water in another tub which I heat over a wood fire for at least 4 to 6 hours. Or, use a bucket heater and a small circulating pump for several days in the larger tanks, depending on the mean outside temperature. (I use one pound of oxalic acid for every two and a half gallons of water- One 55lb bag per 300 to 400 gallon tank. 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 rinsed again and again until it is time to pack them. Then, of course, all the while being very careful and admiring them! Whew! Then the selecting, wrapping and packing begins. Fitting all the crystals into boxes is a living 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 foamy mats when placing them in the van. Extreme caution is exercised during these procedures. They get packed in with foamy mats and blankets and boards, and a helper, when needed!
Then wrap, pack and load. OR.., start the process over for all the re-dos that came out with mineralization still on them.
***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..