RockHoundBlog

Oregon Sunstone

Filed under: Mineral of the day,Rare Rocks!,Video — Gary October 31, 2010 @ 10:49 am

world’s largest  Oregon Sunstone:

A variety known as Oregon sunstone is found in Harney County, Oregon and in eastern Lake County north of Plush. Only Oregon sunstone contains inclusions of copper crystals. Oregon sunstone can be found as large as three inches across. The copper leads to varying color within some stones, where turning one stone will result in multiple colors. The more copper within the stone, the darker the complexion.

On August 4, 1987, Oregon State Legislature designated Oregon sunstone as its state gemstone by joint resolution.

Oregon sunstone

Oregon Sunstone

Sunstone is a plagioclase feldspar, which when viewed from certain directions exhibits a brilliant spangled appearance; this has led to its use as a gemstone. It has been found in Southern Norway, and in some United States localities. It is the official gemstone of Oregon.

The optical effect appears to be due to reflections from enclosures of red haematite, in the form of minute scales, which are hexagonal, rhombic or irregular in shape, and are disposed parallel to the principal cleavage-plane. These enclosures give the stone an appearance something like that of aventurine, whence sunstone is known also as “aventurine-feldspar.” The optical effect called shiller and the color in Oregon Sunstone is due to copper. In the middle part of this crystal, it sparks a lot, and usually has a dark color in the middle, and the color becomes lighter as it becomes the outer part.

Sunstone Mining

Sunstone Mining

Sunstone

Sunstone

The feldspar which usually displays the aventurine appearance is oligoclase, though the effect is sometimes seen in orthoclase: hence two kinds of sunstone are distinguished as “oligoclase sunstone” and “orthoclase sunstone.”

Distribution

Sunstone was not common until recently. Previously the best-known locality being Tvedestrand, near Arendal, in south Norway, where masses of the sunstone occur embedded in a vein of quartz running through gneiss. Due to the discovery of large deposits in Oregon, Sunstone is now readily available.

Other locations include near Lake Baikal in Siberia, and several United States localities—notably at Middletown Township, Delaware County, Pennsylvania, Lakeview, Oregon, and Statesville, North Carolina.

unpolished_sunstone

Unpolished Sunstone

The “orthoclase sunstone” variant has been found near Crown Point and at several other localities in New York, as also at Glen Riddle in Delaware County, Pennsylvania, and at Amelia Courthouse, Amelia County, Virginia.

Sunstone is also found in Pleistocene basalt flows at Sunstone Knoll in Millard County, Utah.

n the short video below you will see the process of prospecting for Oregon sunstone with the use of a drill. As drilling begins we watch the cuttings coming out of the hole. With experience you can tell when it is time to check the cuttings more closely. The drilling penetration rate will vary depending on the type of material being drilled. The color and size of the particles will also vary.The bore hole is cleaned out by compressed air. Compressed air is pumped down the inside of the drill pipe and through the bit. The cuttings are blown to the surface and caught by hand for examination. If you are drilling in a potential mining site there will be ground up particles of feldspar in the cuttings. When you find feldspar in the cuttings you note how much drill pipe is in the hole being drilled. This will tell you how deep to dig with heavy equipment. The video will give you a better understanding and appreciation of what it is like to prospect for sunstone.

Thanks Wikipedia

Cleaning Crystals

Filed under: Cleaning Rocks,DIY Videos,Video,how to? — Gary October 28, 2010 @ 6:44 am

Its an easy 3 step procedure-

1-First step is critical -the clay/mud must be washed off the crystals- a toothbrush is good if you have a small piece to clean.  Larger pieces can be placed in the sun for a day then cooled down in the shade and then given a wash with the garden hose.  Repeating the sun process will dry and crack the clay and make for an easy rinse with the hose.    You can use a pressure washer as well if clay is hard to get off.

2- Removing the iron:  If the crystal has a very light iron staining then a few days soaking in a weak oxalic acid solution will do the trick -covered bucket.

**If iron staining is heavy then you must “cook”  the quartz in an acid solution

3-The most commonly used chemical for cleaning quartz is oxalic acid which may be purchased in a powder form.  When mixed with water at a few ounces per gallon and then heated to just below a boil it is capable of removing all but the most stubborn iron stains.  WARNING – fumes are toxic and very dangerous.  Only do this outside away from children and wearing protective gear.

** A slow cooker or crock pot works well.

**If your specimens begins to grow a white powder as they dry, place them back in a clean crock pot, add water and a 1/3 a cup of baking soda, and cook overnight. This will neutralize the remaining acid as it comes out of the nooks and crannies of the specimens. If this does not work to get rid of the white powder problem, then you will need to cook them again in clean water with baking soda as a neutralizer.

I have had to clean small crystal clusters as many as 5 times before coming totally clean, have patience.

I have also used the product “Iron Out” as well.  It is sold at places like Walmart and is used to get rid of rust stains in sinks and toilets.

RockHound Tshirts

Filed under: regular postings — Gary October 27, 2010 @ 10:57 pm

COMING SOON…

RockHound t-shirts

RockHoundBlog t-shirts

Geology t-shirts

Lapidary T-shirts

(email me with ideas/wants/needs for rockhound themed t-shirts)

rockhoundblog@yahoo.com

I am in the process of designing/making RockHoundBlog t-shirts.  The proceeds will go to a  rockhound friend who is trying to raise money  for a cutting edge  MS surgery (CCSVI).

She has a blog that is recounting her life with MS (Multiple Sclerosis) and is starting from the beginning and telling it like it is.  Very interesting to say the least.  Stop by and wish her luck…

MStrip.ca (MS trip)

Rockhound_fundraiser

Rockhound Fundraiser

Good luck Paula!

Free ebooks

Filed under: Free Books — Gary October 26, 2010 @ 9:17 pm

I had this website passed along to me.  Many free downloads (in French) but you can always use Google Translate.

Kasuku

Kasuku - Free geology ebooks

Here are some links-

Sommaire
(chaque rubrique peut être téléchargée séparément)

The rest (30 on the first page alone)
g-

Make Your Own Rock Tumbler

Filed under: DIY Videos,Video,how to? — Gary October 24, 2010 @ 2:56 pm

I get a lot of feedback about people making their own rock tumblers.  These videos show  how to make them yourself and what they look like- DIY rock tumblers.  If you want to submit your own step by step rock tumbler instructions or video just send me an email.

This is a very inexpensive one that works!

Thanks and enjoy, Gary-

Components:

- Salvaged 1/5hp AC motor from a whole-house exhaust fan

- 4 pillow block bearings ($9.95 each on eBay)

- Fan belt ($9 from Farm & Fleet)

- 3/4″ FIP black iron pipe ($6.50 for each 2′ piece at Menards)

I had to grind 1/16 of an inch off the circumference of each end of the iron pipes to get them to fit inside the 1″ bearings. I went through two bench grinder wheels doing it. Wooden 1″ dowels would be a simpler, easier solution.

Just make sure there’s adequate airflow to keep your motor cool.

-

American Opal Society

Filed under: Coming Events — Gary October 23, 2010 @ 11:14 pm

The American Opal Society proudly presents its:
43rd Annual OPAL & GEM SHOW
Come visit the Biggest Opal Show in the USA!!!

WHAT:

*  Dozens of Opal and Gem Dealers from around the USA and Australia.
Rough and Cut Opals, Opal Jewelry, other gemstones, books, tools, etc.
Huge Raffle with many prizes of opals, gemstones, jewelry, lapidary tools, etc.
Free Seminars on opals, jewelry making, mining, etc. on Saturday and Sunday.
Free Demonstrations on gemstone cutting, jewelry making, etc.

WHEN:

Saturday, 10am-6pm, November 6, 2010
Sunday, 10am-5pm, November 7, 2010

WHERE:

Same Great Location!

Opal Show

Opal Show

Opal and Gem Show

Opal and Gem Show

White House / West Wing Event Center
1238 S. Beach Blvd.
Anaheim, CA 92804

Located within the Hobby City / Adventure City complex,
at the southeast corner of Beach Blvd. and Ball St.

ADMISSION:

Adults $3.00, children under 15 FREE. Plenty of FREE Parking.
One FREE raffle ticket is included with each paid admission.

FOR INFORMATION, CONTACT:

Gene LeVan at (562) 208-7494; e-mail: fineblackopal@sprynet.com
Corey Kuepper at (714) 736-0581; e-mail rockhwnd@aol.com
Dealer Inquiries welcome

http://www.opalsociety.org

American Opal Society, Inc., P.O. Box 4875 Garden Grove, CA 92842-4875
Contact e-mail: info@opalsociety.org

The American Opal Society is a non-profit organization, educational in nature, whose primary purpose is promoting interest and knowledge of the precious gem opal.

The American Opal Society is an non-profit organization, educational in nature, whose primary purpose is promoting interest and knowledge of this precious gem. If you are an Opalholic (i.e. passionate opal lover), the American Opal Society is for you!!! We pursue the study and sharing of information about OPAL.


Sodalite

Filed under: Mineral of the day,Video — Gary October 18, 2010 @ 4:53 pm
Sodalite

Sodalite

Sodalite is a rich royal blue mineral widely enjoyed as an ornamental gemstone. Although massive sodalite samples are opaque, crystals are usually transparent to translucent. Sodalite is a member of the sodalite group and—together with hauyne, nosean, and lazurite—is a common constituent of lapis lazuli. Discovered in 1806 in the Ilimaussaq intrusive complex in Greenland, sodalite did not become important as an ornamental stone until 1891 when vast deposits of fine material were discovered in Ontario, Canada.

Properties

A light, relatively hard yet fragile mineral, sodalite is named after its sodium content; in mineralogy it may be classed as a feldspathoid. Well known for its blue color, sodalite may also be grey, yellow, green, or pink and is often mottled with white veins or patches. The more uniformly blue material is used in jewellery, where it is fashioned into cabochons and beads. Lesser material is more often seen as facing or inlay in various applications.

Sodalite

Sodalite

Although not similar to lazurite and lapis lazuli, sodalite is never quite comparable, being a royal blue rather than ultramarine. Sodalite also rarely contains pyrite, a common inclusion in lapis. It is further distinguished from similar minerals by its white (rather than blue) streak. Sodalite’s six directions of poor cleavage may be seen as incipient cracks running through the stone. Hackmanite is an important variety of sodalite exhibiting tenebrescence. When hackmanite from Mont Saint-Hilaire (Quebec) or Ilímaussaq (Greenland) is freshly quarried, it is generally pale to deep violet but the colour fades quickly to greyish or greenish white. Conversely, hackmanite from Afghanistan and the Myanmar Republic (Burma) starts off creamy white but develops a violet to pink-red colour in sunlight. If left in a dark environment for some time, the violet will fade again. Tenebrescence is accelerated by the use of longwave or, particularly, shortwave ultraviolet light. Much sodalite will also fluoresce a patchy orange under UV light.

Hackmanite
Tenebrescent sodalite from Greenland – Upon exposure to SW UV (UVC) the sodalite (also known as hackmanite) changes color to a dark purple. This is tenebrescence and is a reversible effect. The color can be faded by a bright light, and the effect can be repeated over and over. The sodalite is also fluorescent a bright orange under LW UV, and under SW UV the glow gradually darkens to a rusty color due to this tenebrescence.

Occurrence

Occurring typically in massive form, sodalite is found as vein fillings in plutonic igneous rocks such as nepheline syenites. It is associated with other minerals typical of undersaturated environments, namely leucite, cancrinite and natrolite. Significant deposits of fine material are restricted to but a few locales: Bancroft, Ontario, and Mont-Saint-Hilaire, Quebec, in Canada; and Litchfield, Maine, and Magnet Cove, Arkansas, in the USA. The Ice River complex, near Golden, British Columbia, is being investigated for sodalite recovery. Smaller deposits are found in South America (Brazil and Bolivia), Portugal, Romania, Burma and Russia. Hackmanite is found principally in Mont. Saint-Hilare and Greenland, the latter locale producing a green specimen nicknamed “chameleon sodalite.” Euhedral, transparent crystals are found in northern Namibia and in the lavas of Vesuvius, Italy.

Silver

Filed under: Mineral of the day — Gary October 17, 2010 @ 10:27 pm

Silver

Silver (play /ˈsɪlvər/) is a metallic chemical element with the chemical symbol Ag (Latin: argentum, from the Indo-European root *arg- for “grey” or “shining”) and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal. The metal occurs naturally in its pure, free form (native silver), as an alloy with gold and other metals, and in minerals such as argentite and chlorargyrite. Most silver is produced as a by-product of copper, gold, lead, and zinc refining.

Silver has long been valued as a precious metal, and it is used to make ornaments, jewelry, high-value tableware, utensils (hence the term silverware), and currency coins. Today, silver metal is also used in electrical contacts and conductors, in mirrors and in catalysis of chemical reactions. Its compounds are used in photographic film and dilute silver nitrate solutions and other silver compounds are used as disinfectants and microbiocides. While many medical antimicrobial uses of silver have been supplanted by antibiotics, further research into clinical potential continues.

Silver bullion bar 1000oz bottom view / view from underneath

Silver bullion bar 1000oz bottom view / view from underneath

Silver is a very ductile and malleable (slightly harder than gold) monovalent coinage metal with a brilliant white metallic luster that can take a high degree of polish. It has the highest electrical conductivity of all metals, even higher than copper, but its greater cost has prevented it from being widely used in place of copper for electrical purposes. Despite this, 13,540 tons were used in the electromagnets used for enriching uranium during World War II (mainly because of the wartime shortage of copper). Another notable exception is in high-end audio cables.

Among metals, pure silver has the highest thermal conductivity (the non-metal diamond and superfluid helium II are higher) and one of the highest optical reflectivity. (Aluminium slightly outdoes silver in parts of the visible spectrum, and silver is a poor reflector of ultraviolet light). Silver also has the lowest contact resistance of any metal. Silver halides are photosensitive and are remarkable for their ability to record a latent image that can later be developed chemically. Silver is stable in pure air and water, but tarnishes when it is exposed to air or water containing ozone or hydrogen sulfide to form a black layer of silver sulfide which can be cleaned off with dilute hydrochloric acid. The most common oxidation state of silver is +1 (for example, silver nitrate: AgNO3); in addition, +2 compounds (for example, silver(II) fluoride: AgF2) and the less common +3 compounds (for example, potassium tetrafluoroargentate: K[AgF4] ) are known.

Isotopes

Naturally occurring silver is composed of two stable isotopes, 107Ag and 109Ag, with 107Ag being the most abundant (51.839% natural abundance). Silver’s isotopes are almost equal in abundance, something which is rare in the periodic table. Silver’s atomic weight is 107.8682(2) g/mol.[7][8] Twenty-eight radioisotopes have been characterized, the most stable being 105Ag with a half-life of 41.29 days, 111Ag with a half-life of 7.45 days, and 112Ag with a half-life of 3.13 hours. This element has numerous meta states, the most stable being 108mAg (t1/2 = 418 years), 110mAg (t1/2 = 249.79 days) and 106mAg (t1/2 = 8.28 days). All of the remaining radioactive isotopes have half-lives that are less than an hour, and the majority of these have half-lives that are less than 3 minutes.

Isotopes of silver range in relative atomic mass from 93.943 (94Ag) to 126.936 (127Ag); the primary decay mode before the most abundant stable isotope, 107Ag, is electron capture and the primary mode after is beta decay. The primary decay products before 107Ag are palladium (element 46) isotopes, and the primary products after are cadmium (element 48) isotopes.

The palladium isotope 107Pd decays by beta emission to 107Ag with a half-life of 6.5 million years. Iron meteorites are the only objects with a high-enough palladium-to-silver ratio to yield measurable variations in 107Ag abundance. Radiogenic 107Ag was first discovered in the Santa Clara meteorite in 1978. The discoverers suggest that the coalescence and differentiation of iron-cored small planets may have occurred 10 million years after a nucleosynthetic event. 107Pd–107Ag correlations observed in bodies that have clearly been melted since the accretion of the solar system must reflect the presence of unstable nuclides in the early solar system.

(more…)

Tonopah, Nevada – Silver mine.

Filed under: Rockhound stories,Video — Gary @ 10:01 pm

Came across this article on a silver find in Tonopah Springs.  Very interesting!

Tonopah, Nevada

Tonopah, Nevada

Tonopah Springs, later the site of one of the richest booms in the West, was an Indian campground for many years, long before Jim Butler spent a chilly night here. A number of stories exist as to how Butler discovered the ore. The most popular version is that Butler’s mule wandered away and when Butler found the ornery critter, he noticed an outcropping that appeared to be heavily laced with silver. Butler took a number of samples. The date was May 19, 1900. This quiet start belied the actual importance of the discovery. Butler firmly believed he had discovered an important silver deposit but he had trouble convincing the assayer he visited in nearby Klondike. The assayer told him the samples were worthless, consisting mainly of iron, and he threw them into the back of his tent.
Butler was still convinced that his find was genuine. On his way back to his Monitor Valley ranch, he stopped at Tonopah Springs once more to gather samples. Back at his ranch, Butler put the samples on his windowsill. Not too much time passed before Tasker Oddie, later to be governor of Nevada, stopped at the ranch and spied the ore samples. He offered to pay for another assay and Butler agreed to this. Butler, in turn, offered Oddie a quarter interest of the assay. Oddie heartily agreed. He took the ore samples to William Gayhart, an Austin assayer, and offered Gayhart a quarter interest in his quarter. Gayhart found the assay ran as high as $600 a ton. When Oddie was notified of the value of the samples, he immediately sent an Indian runner to Butler’s ranch to alert him of the rich find. Butler did not react rapidly. He stayed at his ranch to complete the hay harvest and did not even bother to file claims on the lode site! News of the discovery traveled to Klondike and soon, scores of eager prospectors were searching around Tonopah Springs, to no avail, for Butler’s lode. Butler finally went to Belmont, and on August 27, 1900, he and his wife filed on eight claims near the springs. Six of these – Desert Queen, Burro, Valley View, Silver Top, Buckboard, and Mizpah – turned into some of the biggest producers the state has ever had.

Continue reading the article here: Tonopah, Nevada


Matrix (geology)

Filed under: Rockhound Dictionary — Gary @ 9:43 pm
RARE SILVER!!! Sharp, lustrous crystals of Acanthite on Quartz matrix!   It comes from the Victor Mine which was part of the Tonopah Extension Company in Tonopah, Nevada and dates to 1906-1910.    A CLASSIC Nevada Silver specimen from the early Jim Butler days.

RARE SILVER!!! Sharp, lustrous crystals of Acanthite on Quartz matrix! It comes from the Victor Mine which was part of the Tonopah Extension Company in Tonopah, Nevada and dates to 1906-1910. A CLASSIC Nevada Silver specimen from the early Jim Butler days.

To buy this silver on matrix go here: http://www.exceptionalminerals.com/saleroom2.htm

The matrix or groundmass of rock is the fine-grained mass of material in which larger grains or crystals are embedded.

The matrix of an igneous rock consists of fine-grained, often microscopic, crystals in which larger crystals (phenocrysts) are embedded. This porphyritic texture is indicative of multi-stage cooling of magma. For example, porphyritic andesite will have large phenocrysts of plagioclase in a fine-grained matrix. Also in South Africa, diamonds are often mined from a matrix of weathered clay-like rock (kimberlite) called “yellow ground”.

The matrix of sedimentary rocks is a fine-grained clay or silt in which larger grains are embedded. It is also the rock material in which a fossil is embedded.

Cementations

All sediments are at first in an incoherent condition (e.g. sands, clays and gravels, beds of shells, etc.), and in this state they may remain for an indefinite period. Millions of years have elapsed since some of the early Tertiary strata gathered on the ocean floor, yet they are quite friable (e.g. the London Clay) and differ little from many recent accumulations. There are few exceptions, however, to the rule that with increasing age sedimentary rocks become more and more indurated, and the older they are the more likely it is that they will have the firm consistency generally implied in the term “rock”.

The pressure of newer sediments on underlying masses is apparently one cause of this change, though not in itself a very powerful one. More efficiency is generally ascribed to the action of percolating water, which takes up certain soluble materials and redeposits them in pores and cavities. This operation is probably accelerated by the increased pressure produced by superincumbent masses, and to some extent also by the rise of temperature which inevitably takes place in rocks buried to some depth beneath the surface. The rise of temperature, however, is never very great; we know more that one instance of sedimentary deposits which have been buried beneath four or five miles of similar strata (e.g. parts of the Old Red Sandstone), yet no perceptible difference in condition can be made out between beds of similar composition at the top of the series and near its base.

The redeposited cementing material is most commonly calcareous or siliceous. Limestones, which were originally a loose accumulation of shells, corals, etc., become compacted into firm rock in this manner; and the process often takes place with surprising ease, as for example in the deeper parts of coral reefs, or even in wind-blown masses of shelly sand exposed merely to the action of rain. The cementing substance may be regularly deposited in crystalline continuity on the original grains, where these were crystalline; and even in sandstones (such as Kentish Rag) a crystalline matrix of calcite often envelops the sand grains. The change of aragonite to calcite and of calcite to dolomite, by forming new crystalline masses in the interior of the rock, usually also accelerates consolidations. Silica is less easily soluble in ordinary waters, but even this ingredient of rocks is dissolved and redeposited with great frequency. Many sandstones are held together by an infinitesimal amount of colloid or cryptocrystalline silica; when freshly dug from the quarry they are soft and easily trimmed, but after exposure to the air for some time they become much harder, as their siliceous cement sets and passes into a rigid condition. Others contain fine scales of kaolin or of mica. Argillaceous materials may be compacted by mere pressure, like graphite and other scaly minerals.

Potassium feldspar crystals in a granite, eastern Sierra Nevada, Rock Creek Canyon, California.

Potassium feldspar crystals in a granite, eastern Sierra Nevada, Rock Creek Canyon, California.

Thanks wikipedia