New Mexico Mineral Symposium — Abstracts

All mineral specimens require cleaning, and most require some trimming or other preparation. The first cleaning takes place sometime after the specimen is collected, and there are periodic cleanings that need to take place after sitting for years in someone's collection. No one has perfected a dust-free case, especially in Arizona. With a few basic tools and supplies and a bit of knowledge and common sense, any collector can keep their specimens looking nice. There are additional techniques that an advanced collector can use or should be left to a professional. It depends on the willingness of someone to handle chemicals and, more importantly, dispose of them properly when finished.

Trimming is a process that is usually best left to someone who has the tools and the experience to do a proper job. Anyone who has field collected has done some trimming, especially to get that one-pound specimen separated from 100 lb of rock or at least light enough to get it back to the truck and take it home. There is way more to trimming than a chisel and a 3 lb. sledge hammer, not just in finesse but in the end result. However, no matter how many years of experience someone has or however many tools they have at their disposal, there is always a risk when trimming any specimen. The years of experience and, the shop full of tools just help to minimize that risk.

Getting started

You need some equipment to get started. Nothing fancy but the following list will give you the ability to clean most of your specimens, especially if they were acquired from someone who already performed a professional cleaning. This list will provide you with the basics.

- Brushes, ranging from toothbrushes to artists and paint brushes.
- Two plastic wash tubs (three is better)
- Several different sizes of "Tupperware" type plastic containers
- Dish strainer and newspaper
- Tap water-nature's most powerful solvent (wash water)
- Distilled or demineralized water (rinse water)
- Liquid dish soap
- One or more books-Sinkankas' Gem and Mineral Data Book is my recommendation
- Common sense

When setting up to clean minerals, use two tubs of water, one for the soapy wash water and one for the rinse water. You can even do an intermediate (third) one to save your rinse water by having a post-wash/pre-rinse tub of tap water. The final rinse is done in distilled or demineralized water to keep the dissolved minerals in our water from leaving any scum on your specimens, much like what builds up on your drinking glasses.
Here are some dos and don'ts:

1. Do make sure the mineral(s) is not water (or whatever liquid you are using) soluble. Do not overlook this one. I know of someone who once placed a crystallized chalcanthite in their fish tank.
2. Keep your water clean. The wash water will get dirtier much faster than the rinse water.
3. Do make your specimens and water about the same temperature. Some minerals, like cerussite and sulfur, are very temperature sensitive. Others, like quartz, are sensitive if the quartz is at 50° and the water is 110°.
4. Don't use your spouse's fancy Tupperware, unless, of course, it is an emergency. There are plenty of good, inexpensive plastic containers at your local grocery or department store.
5. Do make sure your minerals are not sunlight sensitive if you are washing and drying specimens outside. Cinnabar and silver minerals will darken, topaz will lighten.
6. Don't try to wash fuzzy minerals in water without knowing how strong the crystals are. Not all acicular crystals are equally strong, and the weight of the water can mash the crystals down. However, if you decide to try it, gently lower the specimen into the water, preferably upside down, don't swish it back and forth, and bring it back out. Continue to hold it upside down until most of the water has drained off.
7. Do understand what dissolves the minerals you are working with. For example, warm water is fine for malachite, but warm to hot water can begin to attack azurite and dull bright crystal faces.
8. Don't use drying chemicals, such as acetone or alcohol, without checking out the effects on a poor specimen. These chemicals can pull water out of some minerals and have detrimental effects on the crystals.

Advanced tools:

- Dental picks. Don't buy these, just ask your dentist for some he or she is ready to throw away.
- Ultrasonic cleaner. For delicate crystals or dirt in crevasses you cannot reach with brushes.
- Crock pots. Heat does accelerate chemical processes.
- Do-it-yourself car wash or high pressure water sprays/guns.
- Acids and bases. Ammonia to Lime Away to vinegar, citric acid, and oxalic acid (poisonous) to hydrochloric, hydrofluoric, nitric, and sulfuric acids. All need to be treated with respect and require personal protective equipment.
- Safety equipment:
• Respirators
• Protective gloves. Make sure the gloves are made to protect you from the solution you are working in.
• Safety glasses/face mask
• Apron
• Fan/ventilation

Common sense is truly important when using high pressure water sprays. On one hand, it is amazing the number of minerals one can use high pressure water on. On the other hand, it is equally amazing the number of minerals one should not use high pressure water on. ALL fuzzy minerals are off-limits unless your intent is to try to blast a bunch of the minerals away from another more desirable mineral. Minerals with cleavage, such as calcite and topaz, need to be respected for possibly coming apart.

Only a few of the acids will be dealt with in this presentation. Vinegar and citric acid, as well as Lime Away, are readily available and can be used to dissolve calcite away from other minerals. Oxalic acid is easy to use and very effective for removing iron oxide stains from quartz. However, it is very poisonous so care must be taken to keep animals and children away from the tubs. Also, you do not want to use it on calcite or anything with calcium in it because it will form calcium oxalate, an off-yellow precipitate that is insoluble. Hydrochloric acid is readily available as pool (muriatic) acid, cheap as strong acids go, and very effective in removing rust stains. It requires significant time to neutralize to ensure no yellow iron stains precipitate out and sometimes just is not worth the trouble.

Strong acids and bases need to be respected and used by those who are experienced. Whenever using acids, let the specimen sit in tap water for several hours before putting the specimen into the acid solution. This allows any fractures or cracks to fill with water. Once the specimen is clean, baking soda is a very good neutralizing agent. Ammonia works well, but it can sometimes have interesting side effects on some minerals. Always neutralize the solution before disposing of it.

Trimming

The main purpose of trimming is to remove excess matrix so that the prominent mineral and crystals are not overwhelmed by a large amount of extraneous material. Trimming also gets done so a specimen will fit into a certain size category required by the collector. There are some who object to trimming, either because they are afraid to have it done, or because they believe that somehow a specimen should remain just as it came out of the ground. To preserve a specimen just as it came out of the ground makes no sense, unless there is something significant about the matrix. The amount of matrix that is part of a specimen is just an accident. Specimens need to be trimmed, if for no other reason, than to decrease the amount of space each collector needs to house and display their collection.

Successful trimming is a matter of three things.

- First, the willingness to do it. If you are afraid of breaking something or splitting the specimen, certainly valid reasons for not trimming, then don't.
- Second, once you get past your fears (some collectors I know swear that a stiff shot of alcohol helps, but I do not recommend it), then trimming is like the advice on how to get to Carnegie Hall: practice, practice, practice. If you just purchased a flat of minerals to get the one the seller made sure was in there so you would buy the entire flat, you can start with the worst specimen and work your way to the best one. It is all about knowing how the matrix and crystals will react when trimmed. For example, the limestone that surrounds quartz crystals from Diamond Point, Arizona, splits very nicely in a hydraulic trimmer. The New Jersey basalts, while appearing to be just as solid and homogeneous, are actually shot through with fractures and when placed in a trimmer break with very little predictability.
- Third, it is a matter of having the right tools, which can be anything from tile nippers to diamond saws and micro-abrasion units.

Basic tools that will get you started.

- Tile nippers or horseshoe clippers-available at hardware stores or home improvement stores
- Screwdrivers
- Screw-type trimmer
- Safety equipment
• Gloves
• Glasses, goggles, or face shield. You will experience flying bits of rock and minerals.

The more advanced trimmer/preparer will require some or all of the following:

- Hydraulic trimmers, preferably the German "Zuber" trimmer
- Micro-abrasion units, these require an air compressor
- Dermal tools
- Air scribes, also require an air compressor
- Diamond saws
- Air compressor

The basic tools are readily available and relatively inexpensive. They are limited in what you can do but very effective. Screw-type trimmers are especially effective for smaller specimens and micromounts. Larger specimens will require hydraulic trimmers and diamond saws. One can easily have $10,000 to $20,000 in trimming equipment in order to minimize risk and ensure success.

The only Zuber that is available on the market is the smallest of the three. Chinese imitations were on the market for a while, and the most successful ones were those modified by Dennis Beals in Denver, Colorado. There are plans and designs for trimmers utilizing automotive hydraulic jacks. Screw trimmers are available commercially or can be home made.