Tuesday, April 3, 2018

Why will Ruby Mountain5 Rocks be closed in May?

Between now and April 22, Ruby Mountain5 Rocks is having an inventory reduction sale.  35% off all orders up to $300, 50% off orders over $300 - no coupon needed.  Why would I do such a crazy thing?  - Because sometimes life takes unexpected turns and you have to roll with it. 

Two important things will be happening in May - my field trip with students to my dinosaur dig in Utah, and I will be moving to a new house.  I am excited, exhausted and a bit nervous, but finally, after many years of thinking about it and attempting it - after 8 months of preparing and hoping it would have happened sooner - I finally sold the house where I have been living, which is too big for just me and Reddie (we lost Angus in January).  I will be getting a house where I won't have to worry about goinng up and down stairs, and old Reddie won't either.  However - my new house is not available until June, and my old house sells at the end of April.  So, if I am going to move all my inventory - I might as well move it to your house! 

I won't possibly be able to get all of my inventory posted on the website between now and the end of April, along with moving and packing and everything else that goes with all that.  I am going to work on adding inventory as much as I can, so I encourage you to check back.  If you are looking for something you think I might have, please ask! 

For the majority of May, I will be in Utah with my students on a dinosaur dig.  I do this every year, and this year I am planning to go twice.  We are working on collecting Jurassic dinosaurs and other animals that lived in the area.  The main dinosaur at our site is a Barosaurus - a sauropod dinosaur (long neck and long tail).  It is HUGE and is taking a lot of effort.  We spend out time camped out in the desert near our site, working hard during the day and hanging out by the campfire at night.  It will be a lot of fun, but I won't be near my inventory during that time. 

So, come check out the rock slabs and minerals at www.rubymountain5rocks.com


Sunday, February 4, 2018

Making mitered corners with a trim saw

On my Facebook page, one user mentioned that he wanted to make stone boxes but he could not figure out how to make mitered corners with his trim saw.  Since this is not all that uncommon of a project, I figured it would be relatively easy to find a tutorial on it.  However, after some searching, I found no such thing.  So, I created my own.  This will be the first part of the tutorial - making the miter cut.  Later, I will actually make a box and will post about that process. 

Remember in all you do - measure twice, cut once :). 

Tools used:

1.  Wood miter saw or miter box
2.  Rock trim saw, preferably with a rip fence or other guide to keep your cut straight
3.  Block of wood at least as thick as the stone you want to miter
4.  Enough stone slab of equal thickness to make the size box you want
5.  Tape measure
6.  Sharpie
7.  Cheap 5 minute epoxy
8.  Strong, preferably waterproof epoxy
9.  Rubber bands
10.  Second block of wood, preferably as large as the slabs you are trying to connect

Ok ... you are ready.  Note that my regular little trim saw is dead, so I am using what I normally use to cut slabs.  Same concept though. 

1.  First, you need a guide that will guide the slab through the saw at a 45 degree angle.  Use your first block of wood for this and a miter saw.  Set the miter saw to a 45 degree angle.  Cut the edge of the block of wood to forty five degrees.  If you have a longer piece of wood, it doesn't matter so much where you cut it, you just want to make sure the cut goes all the way to the bottom of the wood.

2.  Set the miter saw to zero degrees.  Cut the tip of the 45 degree angle off.  Ideally, you will want the thickness of the par you cut off to be equal to the cut angle of the slab (the red line in the figure below).  You can calculate this if you know the thickness of the slab, and you know you are cutting a 45 degree angle, using the cosine of the angle.  If this ia a foreign language to you, you can also just measure it.

Also, if you are going to be using the block for more than one slab, they may not all be the same thickness.  It is not critical that this measurement be the same, as long as it is equal to or greater than he thickness of the slab when it is cut.

3.  Your result will be a block with a 45 degree angle with the tip cut off.  

4.  Next, measure the size of the slab that you want the outside of the box to be, the side that is not mitered.  Keep in mind that the inside of the box will be approximately 1/2" less due to the miter.  

 5.  Cut the slab to size, being sure to cut straight.  Use a rip fence or guide to help keep the slab straight.  For reasons described below, you may want to cut the slab a little bit bigger than the size you want it to end up.

6.  At this point it is best to glue the slab to the wood using a cheap 5 minute epoxy.  This will ensure that the slab doesn't move when you are cutting it.  It may say "5 minutes", but really you want to let it cure competely.  A few hours or even over night would be ideal.  For this reason, you may want to have more than one block, so you can cut all the pieces at once.  

Here, if you cut the slab to the exact size you want, you will need to cut the slab so that the mitered edge, just hits the bottom tip of the slab.  If you cut the slab a little bit bigger, you need to align it s that the saw hits the bottom of the slab at the point you want the outside of the box to be.  The benefit of the latter is that if you cut it too big, you can still trim it down.  

7.  Once you have determined where you need to cut, adjust your rip fence of guide so that it holds the slab straight at that position.  As this saw does not have a rip fence, I used a block of wood pushed against the side of the saw so that the gap between the wood and the saw blade positioned the slab where it was needed.  

8.  Once you have mitered the corners of your slabs, you will want to smooth them down so they fit tightly.  Use whatever lapidary means you available to make the mitered edge smooth and straight.  It does not need to be polished, no one will ever see it.  Finally position the two mitered slabs together.  Ensure they fit well, then use a high grade epoxy, preferably a waterproof one, to hold the slabs togher.  

9.  You will need to hold the slabs together while the epoxy dries.  If you happen to have an angle clamp, great - use that.  If you don't - position a block of wood in the corner so the two slabs are tight against the wood.  Make sure the mitered corner does not come apart.  Then tightly wrap rubber bands or string around them to hold them in place.  Allow them to dry for 24 hours.  

Onc you have mastered cutting mitered corners, you will be on your way to making a box!  In a later blog, I will actually make a box.  Stay tuned.

Dr. Janet Bertog, Ruby Mountain5 Rocks

** a special thank you to Stanley Bertog for providing advise on construction ideas, such as how to hold the mitered corners together while they dry.  

Saturday, January 27, 2018

Once in a super blood blue moon

Many have heard the expression "once in a blue moon".  How many know what it means?  Well, this month, we are going to experience an even more rare occurrence - a super blood blue moon. 

The term "once in a blue moon" is used to refer to an event that is so rare that it is unlikely to occur.  This phrase stems from the old definition of a blue moon.  The definition of a blue moon has changed over the years.  In the Farmer's Almanac, a blue moon referred to the third full moon in a season that contained four, rather than the normal three.  In 1946, a misunderstanding of the definition changed it to mean the second full moon in a month.  A blue moon happens on average every two and a half years (1).  This year, however, we will have blue moons in January and March, with no full moon in February.  Although it is rare, the moon will actually appear blue if contaminants are in the sky, such as volcanic ash or fire ash.  As luck would have it, Mount Mayon and several other volcanoes are erupting currently in the Pacific Ocean, and not so nicely either (2). 

Image result for Blue moon

A super moon is when the moon appears bigger than a regular full moon.  This happens because the moon's orbit around the sun is not a perfect circle.  Sometimes it moves a little further away from the Earth and sometimes a little closer.  When the moon is at its closest to the Earth at the same time as a full moon, we get a super moon.  The term super moon was coined in 1979 by astrologer Richard Nolle (3).  A super moon may look about 16% bigger and brighter than an average moon, though it is often not that noticeable to most people.  Because the gravitational pull of the moon affects the tides, during a supermoon, the tides are about 5cm higher than normal as well.  This month we had two supermoons. 
Image result for supermoon

A lunar eclipse occurs when the Earth passes between the sun and the moon, blocking the sun's reflection on the moon.  The moon does not go completely black during this time, but instead turns blood red, hence the term blood moon.  Because of the combination of the supermoon with the eclipse, scientists will have a unique opportunity to see what happens when the moon cools quickly (4).  In this situation, the surface of the moon will cool in a matter of a few hours, rather than seeral days as it normally does. 

So, on January 31, all three of these events will happen at the same time, a phenomena that has not occurred in over 150 years.  If you are interested in finding out when you will be able to view the eclipse in your area, visit this website:  https://www.timeanddate.com/eclipse/map/2018-january-31.

(1) https://phys.org/news/2018-01-total-lunar-eclipse-trifecta-january.html
(2) https://www.volcanodiscovery.com/erupting_volcanoes.html
(3) https://www.timeanddate.com/astronomy/moon/super-full-moon.html
(4)  http://earthsky.org/space/what-scientists-can-learn-during-january-31-lunar-eclipse

By Dr Janet Bertog
Owner Ruby Mountain5 Rocks

Sunday, December 10, 2017

Cabbing soft stones

Have you ever wanted to make a cab out of a soft stone, but worried about ruining the stone in the grinding and polishing process?  Soft stones include such things as talc, gypsum, anhydrite, angelite, and even calcite.  One advantage of soft stones is that they are easy to cut and shape into whatever shape you desire.  Here I present the method I used to make an angel cabochon from angelite.

First, I rough cut the cabochon from the slab.  It was easy to cut fairly close to the shape I wanted even with the trim saw. 

Next, I finished cutting and shaping the angel with a diamond saw blade and stone shaping tool on a dremel.

Next, I ran the stone under hot water for 15 minutes.  This smoothed the rough edges fairly well.

Then, I used a 600 grit diamond wheel, very lightly for a short period of time to remove the scratches from my drawing the shape.  Then I moved to a 1200 grit diamond wheel until it was smooth.  Finally, I finished the polish with a 14000 grit diamond wheel.  None of these steps took more than a couple of minutes.  
Angelite finishes to a nice satin finish.

Finally, I wire wrapped the stone into an angel.

Dr. Janet Bertog, owner

Thursday, November 9, 2017

Using Butvar (polyvinyl acetate) for stabilizing stones

Sometimes it is necessary to stabilize rocks before cutting and polishing them.  Stones with fractures, porous stones or brittle stones will benefit from stabilization, allowing you to cut and shape them without risking the loss of the stone.  Typically, I hear of three primary methods of stabilizing stones.  I will summarize these methods below.  Then, I would like to introduce you to a material that is used by museums to stabilize fossils and artifacts.  This material, butvar, is a polyvinyl acetate and is used by museums because it does not deteriorate even after very long periods of time and it does not discolor.  It has an added advantage that it can be mixed to any consistency desired, so you can make a thin penetrant or a thick glue with it.  I have used this material to stabilize stones before cabbing them with success.

Typical methods of stabilizing stones

1.        Backing:  A backing is applied to stones, most commonly turquoise and opal, in order to keep the stone “natural” while holding the fragile material together.  Backing is simply applying a thin layer of material to the back of the stone that will help hold the stone together.  This mostly helps porous stones stay together and helps to keep stones together that have fractures.  Backing material varies widely.  Sometimes, a thin piece of stone is adhered to the stone.  Then the stone is cut and polished as normal.  Backing is not used if the back of the stone may be visible in the finished product.  Backing materials include basanite, black jade (typically a dark stone), or synthetic materials.  Devcon epoxy, an epoxy with metal in it, is sometimes used.  JB Weld, another metal epoxy, is also common.  A thin layer of the epoxy is applied and allowed to dry completely before the stone is cut and polished.

2.        Thin cyanoacrylate (“super glue):  Thin super glue can be applied to a stone with fractures or pits.  The superglue will fill the fractures and pits, holding them together.  While this method may work for fractures and pits, I have not had luck with using it to stabilize a generally fragile stone.  Most often the glue just forms a coating on the surface of the stone, which easily peels off during the cutting process.

3.        Epoxy Resin

Opticon resin:  I have heard mixed results about this material.  Some people swear by it, others hate it.  Opticon is a thin resin that is supposed to dry water clear, so it does not discolor the stone.  It can be used to impregnate a porous stone, so it fills a niche the first two methods do not.  It can be a little tricky to use.  For a description of using Opticon, see these instructions on the mindat website:  https://www.mindat.org/article.php/1129/Methods+to+Stabilize+Material+for+Cutting

Standard epoxy:  I found reference to using epoxy dissolved in acetone on this discussion board:  http://forum.rocktumblinghobby.com/thread/15452/stabilizing-procedure-crumbly-lapidary-rough?page=2#ixzz4xrfEbGnn.  Note that I read elsewhere that it says to use equal parts of epoxy and acetone.

Butvar Polyvinyl Acetate

There are a few different types of butvar that have different molecular weights.  The two most common are B-72 and B-98.  I have used both of these in my museum work.  Typically we used B-72 in fossils that were rather wet, but mostly we used B-98.  B-72 can be dissolved in alcohol or acetone.  B-98 should be dissolved in acetone.  Note:  Please use caution with these materials.  They are not toxic and they will not hurt your skin, but the acetone can.  The acetone is a known carcinogen and it is recommended that you wear gloves and eye protection when working with it.  Do not get it in your eye – you will glue your contact to your eye and it will scratch the surface of your cornea (sure, ask me how I know!!).  For the most part though it is very safe.  We use is all the time on fossils in the field and the lab.  I will mention a couple of different methods for using butvar to stabilize your rocks. 

1.     Mix a thin consistency of acetone and butvar in a container that has a lid.  There should be enough butvar in the container so that it will actually work, but it should still be water thin.  So add butvar, and if it starts getting thick, add a little more acetone to thin it back out.  The amounts are not critical.  You will want a large enough container and enough of the mixture to cover the stone you are working with.  Put the stone in the container.  Let it sit for several days, 4-7 is recommended.  During this time, It is advised to shake or  stir the container.  I found shaking most useful in order to stir the stone around in the container.  One option, which I have not done, but I plan to try at some point, is to put the stone in a container where you can add suction to it.  I am thinking like a space bag, where you put things in the bag then use a vacuum to suction it.  If you do this, you would want to apply suction to pull the butvar solution up, but NOT suck it completely out of the container.  Repeat this several times.  The advantage of doing this is that it will force the butvar into the stone and there will be less wait time. 

2.     What I found to be most efficient was to create a thin concentration of butvar in the acetone, it needs to be pretty thin the penetrate the rock.  Then I put the rock on a piece of plastic wrap and pour the butvar over it (this is the method we use in the field, especially when the bone is still in the rock and we can’t soak it).  I will do this, let the acetone evaporate, and continue doing this until is does not evaporate within about 10-15 seconds.  Then I know the butvar has penetrated as much as it can.  I turn the rock over and repeat on the other side.  Then I let it dry for a few hours.  I did not find it necessary, but it was suggested that if you heat the stone before applying the butvar it well help to open the spaces. 

I have a new material I collected from North Carolina, which I call Mountain Petronella.  It has very soft minerals mixed with hard minerals and they have a lot of planes of weakness in them.  I was not able to cab this material but when I stabilized it with butvar, it cabbed great.

Mountain Petronella from North Carolina

I also have a piece of granular peridot, which has individual grains that are very loose.  I was able to stabilize and cab this material as well.
Granular Peridot

Wednesday, October 11, 2017

Red River Gorge, Kentucky

In my other life, I am a professor of geology at Northern Kentucky University.  An important part of my teaching is taking students on field trips to expose them to geology first hand.  Last weekend I took my introductory class to Red River Gorge in Kentucky to study the formation of natural bridges and other associated rock formations.

Red River Gorge is near Slade, Kentucky, about an hour southeast of Lexington.  It is one of the largest collections of natural bridges in the country.  

Red River Gorge is on the edge of the Appalachian Plateau on what is known as the Pottsville escarpment.  In this area, sandstone from the Pennsylvanian Period, about 290 million years ago, is exposed.  This sandstone is relatively resistant to erosion, especially compared to the Mississippian Limestone that lies below it.  As a result, it holds up the edge of the plateau and creates the escarpment, where it drops down to lower elevations where the Mississippian limestone is exposed.  

From University of Kentucky department of Geography.  The blue-gray area on the east side of the state is Pennsylvanian sandstone and the lighter blue is Mississipian limestone.  

The region was uplifted along the edge of the Cincinnati arch during the formation of the Appalachian Mountains, which ended in the Permian Age, 245 million years ago.  The uplift warped the continent in this area and made the layers tilted, as shown in the geologic cross-section above.  This causes different rock units to be exposed in different parts of the state, with the oldest in the center of the Cincinnati arch, which is centered on Lexington, and younger rocks found in a bulls-eye pattern around it.  Where the Pennsylvanian sandstone and the Mississippian limestone are exposed together, we get the escarpment.  

The flat tops of the hills are the Appalachian Plateau.  The Red River cut down through the sandstone, exposing it and allowing the formation of the natural bridges.

The limestone was deposited in a shallow sea teeming with life of a coral reef in a shallow sea that formed in the Appalachian Basin, a low area that formed when the Appalachian Mountains pushed up and put weight on the continent, pushing it down.  From the Mississippian to the Pennsylvanian, this basin started to get more shallow and the sandstone was deposited in layers by large rivers flowing off the Appalachian Mountains and into the Appalachian Basin.  During the uplift of the Cincinnati arch, the sandstone was fractured in both a north-south and east-west direction.  

The combination of horizontal layers in the sandstone and the fractures are responsible for the formation of the natural bridges in this area.  Initially, the sandstone starts to weather by grains of sand and pebbles getting plucked out of the sand.  Small holes open up in the sand, and the grains get caught up in the holes with wind and rain and tumble around in the holes opening them larger.  This creates a "swiss cheese" texture in the rock.  
"Swis cheese" texture in the sandstone as little holes open

Eventually, these little holes grow to where they start combining together and open up recessed caves.  Recessed caves are shallow but long and follow the layers in the sandstone.  The layers are zones of weakness in the rock, so the rock weathers more quickly here.  

A recessed cave can be seen under this waterfall at Rock Bridge
The sandstone has horizontal layers that are more susceptible to weathering and open up recessed caves
Because the sandstone is fractured vertically, eventually, the recessed cave will cut through to the other side, where a fracture exposes it, opening a hole in the rock and creating an arch.  Initially this hole is small, but it eventually grows.  Early, the edges of the arch are sharp and blocky, like at Natural Bridge.  But, over time the edges of the bridge weather more smooth, and the arch becomes more rounded.  This is like what is seen at Delicate Arch at Arches National Monument in Utah.

Students under Natural Bridge.  Natural Bridge is sharp and blocky and is a young arch.
Delicate Arch in Utah is an old arch

Eventually, the top of the arch becomes too thin to support itself and it collapses forming pinnacles.  The pinnacles continue to weather along the layers, and form balanced rocks.  Eventually, the balanced rock will collapse, completely destroying the formations.  
Balanced Rock at Natural Bridge State Park

Sometimes, the bridges will form from a river running over the sandstone and cutting down into the fractures.  As the fracture opens, it separates a bridge from the rest of the rock, and forms a waterfall next to the bridge.  Over time, the waterfall will cut upstream, separating from the bridge.  This is the case at Rock Bridge.  The waterfall is now about 1/4 mile upstream from the bridge.
Waterfall formed by Rock Bridge

Rock Bridge with a river flowing under it

Weathering is a process of creation, but it is also a process of destruction.  The formation of the arches will continue to change until ultimately they are destroyed by the same processes that created them.

Saturday, September 9, 2017

Opals and Onyx

Tomorrow, I am releasing the limited edition

opals and onyx collection

showstopping gemstones for every occasion

Opals and onyx are two of the most popular ever-lasting gemstones in the jewelry market.  But what are they ... really?  In a previous post on August 20, I talked about flint and chert.  Today, you will discover that opal, onyx, chert, flint, chalcedony ... they are all essentially variations on the same thing - microcrystalline grains of silica.

Onyx is a banded variety of chalcedony.  The bands are created by alternating layers of microcrystalline quartz and moganite, which is essentially quartz with a different crystal structure.  Sardonyx is a variety of onyx with bands of quartz and sard, another variety of chalcedony.  (Gemstone manufactures seem to try to make their products stand out by giving different names to essentially the same minerals).  Utah blue and orange sardonyx are examples.
Utah Sardonyx collected near Nephi, Utah

Calcite onyx is actually not onyx at all.  Calcite onyx, or cave onyx, is banded layers of calcite that form from cave formations such as stalagtites and stalagmites.  It forms much the same way, with one little layer at a time slowly precipitated.  But it is calcite instead of quartz.  Honey onyx and the most popular flowering tube onyx are examples.
Flowering Tube Onyx collected near Nephi, Utah

Cave Formations at Ruby Falls, Tennesee
Opal is the least like all the other minerals - onyx, chert, flint, and chalcedony.  It is still silica, but in opal, the silica does not form crystals of quartz.  It is a hydrated, amorphous silica "ooze".  Most often, opal is associated with volcanic activity.  Silica-rich fluids from magma flow into the surrounding rock, where the opal is precipitated in pockets and layers in the rock.  The internal structure of the silica ooze makes it refract light, which gives opals their most-sought after feature - sparkle.

There are two types of opal - common opal and precious opal.  I personally feel these names do not do them justice because "common" opal is just as amazing as precious opal.  Precious opal tends to show a play of colors and multi-color sparkle and shimmer that dances in the light.  Common opal tends to be translucent and often a single solid color, or bands of colors.

Examples of common opal include Utah bacon opal and Peruvian pink and blue opal.
Utah Bacon Opal collected near Milford, Utah

Examples of precious opal include the Honduran black matrix opal and koroit boulder opal.

Honduran Black Matrix Opal

All of these stones make beautiful cabs and stunning jewelry perfect for that special occasion or to make every day feel special.

Cabochon from Bacon Opal
Cabochon from Koroit Boulder Opal

Find the Opal and Onyx Collection at www.rubymountain5rocks.com.  Don't forget, join Club Ruby for an instant 20% discount!

Dr. Janet Bertog, owner Ruby Mountain5 Rocks