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Question: I am a member of the Hastings Rockhounds in Vancouver, B.C. I am interested in collecting on the Willamette River in the summer. Do you know of any public access roads to the gravel bars? I checked the Gem Trails of Oregon and it says it is difficult to find public access. Please let me know if you have any maps or info about the area near Corvallis. Thanks
Answer: The Oregon State Marine Board and Oregon Parks and Recreation Department publish a booklet named Willamette River Recreation Guide, which should be very helpful. It shows all the public access sites along the Willamette River, and identifies what facilities are available at those site. The booklet is available on the internet at:
http://www.oregonstateparks.org/images/pdf/will_river_guide.pdf
see page 18-21 for the Corvallis area. If you are traveling with a group, you might want to consider renting canoes or kayaks. That way you would be able to stop at all the gravel bars. Good luck!
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Question: I bought some rocks in Colorado that the dealer called "dinosaur gizzards". He assured me that dinosaurs had used these rocks to digest their food. As I understood him, dinosaurs swallowed rocks, which then tumbled around in their stomachs while digesting food, and then came out somewhat polished. The rocks have a matte finish, which support his story, but on closer inspection, they also have some white specks (tripoli?) in some of the cracks. Was I snookered? If his story is true, how do they know that's how the rocks got polished? Thanks Rocky.
Answer: No, you didn't get snookered Dinasours had a crop like a chicken. They swallowed rocks to grind up food, and eventually passed them. These polished rocks are called gastroliths. The white in the cracks is called collegie, or alkali. It is not uncommon for gastroliths to have a coating of collegie, especially if found near a river.
Rocks can be identified as gastroliths because they are a round smooth rock that seems out of place, they are found in areas dinasours are know to have lived, and you won't find many of them. Some gastroliths have even been found sticking out of copralite (dino dung), which is the best proof of all they came from dinasours.
Question: I’ve always been curious about amber. Is it considered a rock?
Answer: Amber is a fossil resin that contains succinic acid – it is not really a rock. Besides the really cool bugs and bark that get trapped in amber, it has been known for it’s property of generating static electricity from as early as 600 BC (by the Greeks, who called amber ‘elektron’ hence the origin of the english world electricity. Pretty important for not being a rock.
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Question: How come so many minerals names end in “ite”?
Answer: Thats is a very good question. It is also one I have asked myself. To answer it I looked up "ite" in a simple dictionary. "ite" is a suffix added to the root of the main name of a mineral or rock. "ite" can mean native, descendant, product or according to the dictionary I used, mineral. Therefore I would have to say that minerals end in "ite" because it helps describe the nature of a mineral or rock. For example the rock quartzite is named as such because quartz was/is its chief native mineral. Well I hope that helps.
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Question: I’ve been buying some opal at rock shows recently and they are always sold in glass containers with some sort of liquid. Once I get them home I usually take them out and spread them out so that I can see them better. Should I be storing them in liquid. Thanks Rocky, your great!
Answer: Well thank you for asking. As for storing wet or dry, I think it is best dry. I sometimes keep my rough wet in glass domes just to simplify selection of new stones to cut. Once the stones are dried - keep them dry. All my cut stones are also kept dry. Some dry opals crack and craze. But the bottom line is that they will anyway, eventually. Some opals are born to craze. Experts simply don't agree on the causes of opal stability and instability, but here's what I've comUntitled 9e to think over the years based on reading, conversations with experts and my own experience. All opal contains varying amounts of water. Australian opal expert Len Cram's research indicates that good quality, stable Aussie material has about 6% water. Years ago when I was digging for opal at Keith Hodson's Virgin Valley mine in Nevada, Keith told me a couple of stories that make me believe opal instability is caused by mining it several hundred thousand years too soon!
Most Virgin Valley opal simply contains too much water when mined, opal missed in mining and found several years later in the mine-dumps outside, tended to have a much higher percentage of stability. This was presumably due to slower dehydration of excess water, allowing internal "adjustment" to the water loss. While most Australian opal is stable, I've been told that production from new mines is viewed with great caution until proven.
Over the years I've developed the habit of putting all the opals I cut aside for at least 6 months before mounting or selling them. Most problems -- if there are to be any -- show up in that amount of time.
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Question: What is the best glue/adhesive to use for gluing cabachons to findings? I’ve made a cab to fit in a pin, but the prongs seem to be mostly decorative, so I need to use a glue that will definitely hold. What do you recommend? If it makes any difference, the cab is 10 x 14.
Answer: Most of the time, I use the extra thick gap filling crazy glue that I purchase at local hobby stores. There is Leisure Hobbies on Lancaster across from the mall, and Skysport Hobby on S. Commercial. I reason I like this product is that besides filling any gaps caused by undersized cabs or irregularities in the mounting, they also have what they call an accelerator that speeds up the time it takes to cure. Do not get the glue on yourself or it will instantly bound to your skin. With patience, you can remove it by using acetone or fingernail polish remover. There are many other types of adhesives you can use including epoxy and others found at local craft stores.
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Question: What is a dendrite? What kinds of rocks have them?
Answer: Dendrites can be found on rock surfaces and in cracks in rocks. It is a mineral (manganese oxide) crystalli-zing in the form of a branching or treelike mark. http://minerals.gps.caltech.edu/files/dendrite
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Question: My 30x40 and 22x30 cabs always start out oval, but by the time I’m done, they are pointy on the ends and shaped like a football. What am I doing wrong?
Answer: Rocky always says – keep your eye on the outline. As you round the shorter ends back off the pressure and keep moving at the same speed. Since even I slow up on the tight corners, I always leave more outside the line at the ends and come back to finish them after the sides are shaped using only a 200 grit wheel and the tips of my fingers.
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Question: Can you recommend any rock shops near where we’ll be going on the Ochoco field trip?
Answer: I recommend Elkins Gem Stones in Prineville, 972 South Main (near the fairgrounds). And I don't want to forget Quant's Rock Shop.
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Question: Are there some stones that should be tumbled more slowly than others? Which ones? What can I do to slow the tumbling speed?
Answer: Usually you can slow down the big tumblers by changing to a small pulley on the motor, or to a larger one that drives the tumbler shafts. I don't think you can slow down the smaller tumblers unless you get a reostat that gives less power to the motor. Some stones definitely need to be slowed down, mostly obsidians and apache tears. When you can't slow the tumbler speed, add more rock and some type of buffer material (filler) such as saw dust. That is why I prefer to use the vibrator type of tumblers for these materials, which makes it a moot point. Good luck and happy tumbling.
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Question: Can I put less than a full load of rock in a vibratory tumbler?
Answer: Yes, as long as you put enough in so that the rocks turn over.
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Question: Do you ever use polyethylene pellets in the final polishing stage with a vibratory tumbler?
Answer: Pellets can be used. Remember to change the pellets whenever you change grit sizes. You can also use small agates or other rocks with similar hardness. I save pieces from the trim saw and also collect smaller pieces when collecting just to have them on hand for tumbling. Don't tumble obsidian with agate, etc. The most common thing people tumble are quartz-based. Agate. jasper, quartz, etc. which are all pretty much the same hardness.
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Question: There have been articles in the newsletter about members floating down the rivers collecting rocks. What kind of boat are they using? Where do I get one?
Answer: I went to Theresa Byrne, our resident expert on boating the local rivers and creeks for the following answer.
Answer: On larger rivers, such as the Willamette, a row boat or motor boat is fine. But on smaller rivers, you’ll need something light because there will be portages (carrying your boat around downed trees in the water, etc.) An inflatable kayak works great on these trips. The least expensive inflatable is the Sevylor Tahiti. You can get one for about $90 at BiMart. An inexpensive paddle, life preserver and pump will cost an additional $40. Unfortunately, the Tahiti punctures very easily - if you buy one, bring a roll of duct tape on all trips for insurance. Sevylor also makes a heavy duty kayak that sells for about $450 - GI Joe’s sells them. Another inexpensive inflatable is the Sea Eagle 330. It sells for about $200, and includes a paddle and foot pump. They aren’t sold in retail stores. Check them out at www.seaeagle.com, or call 1-800-852-0925 for a catalog.
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Question: Can thick glass be cut with equipment in a traditional lapidary shop? I made a heart in a glass making class that is 1 1/2 inches thick. I would like to cut it into thinner hearts, each about 1/2 inch thick.
Answer: Cutting glass is actually easier than cutting rock with our lapidary equipment. It is just like obsidian in nature and possess no special problems other than when it comes to polishing. Just like if you are going to polish obsidian, it should be the only material that is exposed to the polishing laps. Agate material is harder and tends to contaminate the laps which keeps scratching the glass.
If you want to glue the glass to a piece of wood for additional cutting, you can use a substance called water glass which is used for fixing cracks in concrete found sometimes in hardware stores, or what I like to use is elmers white glue and leave it dry for several days. To unglue, let it soak in water for a while and it will come right off. Good luck and have fun..
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Question: I bought some old rock books at a garage sale. They are great books but they smell very musty. Is there anything I can do?
Answer: Yes! Clorox Disinfecting Spray does a great job. Stand the book up, fan out the pages, and spray the edges of the pages. Let it dry with the pages still fanned out. You will be amazed at the results. Really musty books may require a second spraying. There are other disinfecting sprays on the market, but I haven’t had the same success with them as I have with Clorox..
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Question: What causes the snowflakes in snowflake obsidian?
Answer: There are a couple of theories on how snowflake obsidian formed. The most popular is that is cooled slightly slower than some of the other obsidians so that it started to crystalize. The other is similar, but that the cavities may contain small but beautiful crystals of feldspar and ordinary quartz, and less commonly, iron olivine, topaz, tourmaline, and garnet. Sources of snowflake obsidian include California, Oregon (Crater Lake), Wyoming, and Mexico..
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Question: I will be tumbling obsidian points in a 3# tumbler. Should I follow the same instructions as for tumbling agates and jasper?
Answer: The technique that seems to work best for me - after a lot of experimentation - is to use 220 with sawdust (any filler will work) and check it about every other day until the desired effect is achieved. After cleaning completely, use 400 or 600 for several more days, and preferably use a vibrating tumbler to polish. If using a rotating tumbler for polishing, be sure to load it up with some type of filler (sawdust or whatever) to prevent the obsidian from chipping..
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Question: I have acquired a piece of electric blue obsidian. Like most obsidian I have seen, the chatoyancy is in layers or bands. On the exterior of the chunk, I can make out faint lines across the stone that correspond to the edges of the bands. What is the proper way to orient the cut to give the best results for cabs or even bookends? Should the "slab face" be at the top of the band plus a little so that I can dome through the band? Do I want to have more of a "ringed" effect or "feathered" as I do with petrified wood, (I like to cut 45 off the grain and 45 degrees across the rings)
Answer: Obsidian was one of my first materials that I worked with, and given a little patience and practice, you will produce some of the most beautiful stones around. As with any material, each one has it’s own particular characteristics that must be mastered. Obsidian considered natural volcanic glass comprised mostly of silicon dioxide, or in more easily understood terms, window glass, with impurities that were introduced during it’s molten phase. Black is the most predominant color, but different shades of green has also been found. Some of the most sought after are the ones we refer to as rainbow, fire, mahogany, gem quality black, midnight lace, electric blue, and the pink lady varieties. With rainbow and some of the others, the layering of different minerals has produced a wide variety of color effects within the obsidian.
Some of the most popular collecting areas include Glass Buttes in OR and Davis Creek/Lassen Creek in northern CA. Some real wild colors have also been coming out of Mexico and can be attained at a high price because of it’s quality.
From experience and the people I have talked with that know obsidian recommend to orientate the lines at about a 5&Mac251; angle and when shaping, have the lines angled towards you when you finished with the stone. This works good for bookends and polished slabs, along with most cabs for broaches and bolas.
Most generally you are better off to have a very slight angle to the bands for best color effect. On material that I would like to make a bull’s eye cab, I choose a piece that has extremely close lines or banding. This will give a “ringed” pattern that you are asking for your third question. If you try cutting at 45 degree angle, the bands will be angled so steeply and that you will loose all of the color. There is no hard and fast way to learn which way to orientate the stones except with a lot of experimentation and some luck. Good luck and have fun..
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Question: I can’t seem to get a good polish on my cabachons. Can you help me Rocky?
Answer: The first step to ensure a good polish is that the sanding is done properly. As you progress through sanding grits to the smallest grit, periodically dry the cab and look at the stone for uniform gloss at each step.
Next, wash the stone in warm soapy water, preferably from a tap. Don’t use water that has any sign of oil or dirt for this cleaning and make sure your hands are equally clean.
It is important not to have any oil or grit contaminate the polishing buff. Keep the buff covered when it is not in use. Mix the polish of your choice ( I haven’t ever had a problem with an optical grade cerium oxide on soft or split side leather). With clean water, just enough to dissolve the polish, mix the polish in a clean cup using a paint brush that you use only for this purpose. I store all these things under the cover with the buff when not in use.
Load the polishing wheel heavily brushing on the polish
/water mix. The wheel needs to be damp and the mix thick enough that it ‘plasters’ the buff. The more polish that contacts the rock the faster the polish will be. If you see the buff material - not the polish contacting your stone, load up more polish on the buff. When the buff starts to dry, either add more polish mix or spray with a water bottle.
Use a lot of pressure to get good contact. Turn the stone or rotate it as it is polished, but remember, if the buff is “just right” you will have considerable drag. It will feel like the stone is trying to adhere to the buff when the polish is working at it’s best - so don’t let go. Even a large cab polishes in seconds when the polish is right at that thin mud or plaster-like consistency, but as with sanding, you need to stop and wash the mud off your hands and the stone to see how consistent your shine is.
If you haven’t done the sanding right, you’ll notice the really dull spots in the shine right away. Don’t waste any time trying to polish what needs to be resanded. As with any step in shaping, sanding to polishing, always take the time to “back up” if you truly want the best you can do..
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Question: I’ve heard that people used to collect fossils on Peterson’s Butte near Lebanon. Do you know if this is true, and if it is possible to still collect there?
Answer: If anyone knows has any information on this, please let me know. It may be a new/old place for collecting some fossils..
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Question: I will be tumbling obsidian points in a 3# tumbler. Should I follow the same instructions as for tumbling agates and jasper?
Answer: The technique that seems to work best is to use 220 with sawdust (any filler will work) and check it about every other day until the desired effect is achieved. After cleaning completely, use 400 or 600 for several more days, and preferably use a vibrating tumbler to polish. If using a rotating tumbler for polishing, be sure to load it up with some type of filler (sawdust or whatever) to prevent the obsidian from chipping..
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Question: I have soaked crystals in oxalic acid for a couple of weeks, but they still have rust. What else I can do?
Answer: I too have also experienced rust stains not coming out after using EITHER oxalic or muriatic acid. Another chemical which is a little safer and has worked nicely happens to be sodium bisulfide which is a common compound found in several rust removal substances. The best source for the price is Scott’s Janitorial on 13th St. SE. The product is called “Rust Out” and sell for $5.00. A little goes a long way. It also works great on sinks and toilets after leaving it soak for a short time - very short - usually within an hour. For rocks, just leave it soak for several days and see how it works.
Question: Where does citrine come from? Is the brown color natural? How can you tell the difference between heated citrine and natural brown citrine?
Answer: The primary source of citrine is Brazil. Citrine is yellow quartz, and the color may grade into a smokey brown. The color is due to the presence of iron, though some lemon-yellow quartz on the market derives its color from irradiation, and is not naturally colored. There is no way to tell the difference between heat treated citrine and natural citrine. This is because even natural citrine has been heated..
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Question: Who is the patron saint of rock collecting? Rudy thinks it might be “Saint Igneous”.
Answer: There are patron saints for almost 1200 topics, but unfortunately, “rock collecting” is not one of them. However, by expanding the topic a little, there are two that come fairly close. Saint Eligius and Saint Dunstan are both patron saints for gold workers, goldsmiths, jewelers, metal workers, metal collectors, miners and precious metal collectors.
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