Search Results - Obsidian
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Obsidian is a naturally occurring volcanic glass formed as an extrusive igneous rock. It is produced when felsic lava extruded from a volcano cools without crystal growth. Obsidian is commonly found within the margins of rhyolitic lava flows known as obsidian flows, where the chemical composition (high silica content) induces a high viscosity and polymerization degree of the lava. The inhibition of atomic diffusion through this highly viscous and polymerized lava explains the lack of crystal growth. Because of the lack of crystal structure, obsidian blade edges can reach almost molecular thinness, leading to its ancient use as projectile points, and its modern use as surgical scalpel blades. [1]Obsidian is mineral-like, but not a true mineral because as a glass it is not crystalline; in addition, its composition is too complex to comprise a single mineral. It is sometimes classified as a mineraloid. Though obsidian is dark in color similar to mafic rocks such as basalt, obsidian's composition is extremely felsic. Obsidian consists mainly of SiO2 (silicon dioxide), usually 70% or more. Crystalline rocks with obsidian's composition include granite and rhyolite. Because obsidian is metastable at the Earth's surface (over time the glass becomes fine-grained mineral crystals), no obsidian has been found that is older than Cretaceous age. This breakdown of obsidian is accelerated by the presence of water. Obsidian has low water content when fresh, typically less than 1% water by weight,[3] but becomes progressively hydrated when exposed to groundwater, forming perlite. Tektites were once thought by many to be obsidian produced by lunar volcanic eruptions, though few scientists now adhere to this hypothesis. Pure obsidian is usually dark in appearance, though the color varies depending on the presence of impurities. Iron and magnesium typically give the obsidian a dark green to brown to black color. A very few samples are nearly colorless. In some stones, the inclusion of small, white, radially clustered crystals of cristobalite in the black glass produce a blotchy or snowflake pattern (snowflake obsidian). It may contain patterns of gas bubbles remaining from the lava flow, aligned along layers created as the molten rock was flowing before being cooled. These bubbles can produce interesting effects such as a golden sheen (sheen obsidian) or a rainbow sheen (rainbow obsidian). Glass Mountain, a large obsidian flow at Medicine Lake Volcano
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Showing 1 to 16 of 16 Articles matching 'Obsidian' in related articles. |
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1. free shipping wholesale & retail jewelry
November 13, 2009
www.jewelry-eden.com is an online store which specializes in wholesale and retail jewelry, such as various styles of necklaces, loose beads, pendants, bracelets, brooches, earrings, fashion decoration made of various materials, including jade, amethyst, lapis, turquoise, garnet, crystal, coral, mother pearl shell, agate, opal, tiger eye, obsidian, rose quartz, malachite, hematite, glass bead, coconut craft, etc, besides loose beads and jewelry supplies, we have our DIY fashion jewelry as well. Our products are direct from manufacturer, so we can provide incredible price, which is fairly lower ... (read more)
Author: Sunny Liu
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2. Sony Ericsson Aino : Can't ask for more
November 12, 2009
Sony Ericsson Aino is one handset that has been designed keeping in mind each and every requirement of the user. The handset looks after both the futuristic features as well as amazing craftsmanship and sleek designs the users are looking forward to these days. Obsidian black and luminous white casing of Sony Ericsson Aino leaves no stone unturned to attract attention.
Features at a glance:
The casing which is quite compact measures 10.4cm by 5cm by 1.55cm and weighs 130 grams.GSM network coverage is provided to the handset along with 3G HSDPA network that together ensure that the u... (read more)
Author: Eti Sharma
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3. Sony Ericsson Aino Contract: It is right to use
November 12, 2009
Sony Ericsson Aino is an advanced mobile phone with many amazing features. This high-end handset can be purchased at reduced price through Sony Ericsson Aino Contract.This contract is a win-win situation for both manufacturers and customers. Sony Ericsson Aino is an elegant device that comes in two attractive colors that are Luminous White and Obsidian Black. This handset allow user to play games anywhere and anytime by connecting their handset with the console of PS3 games remotely. Thus they can enjoy playing in their spare time. This merged Sony's Walkman handset with Cyber shot technol... (read more)
Author: Torie Wilson
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4. Glamorous Sony Ericsson Aino
November 03, 2009
Your search for a glamorous phone ends here with Sony Ericsson Aino which has amazing coloured casing of obsidian black and luminous white to offer its users. This 3G phone not only makes life easy but adds on a dazzle to it.
Here are the features of Sony Ericsson Aino:
The handset comes integrated with 55mb of internal memory which like any other handset can be increased with the aid of the memory card at any stage of requirement.Like most of the high end phones, Sony Ericsson Aino too has quad band of GSM network to offer its users for network coverage. Worldwide roaming feature ... (read more)
Author: Eti Sharma
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5. Sony Ericsson Aino Contract: Get Amazing Offer
October 08, 2009
Sony Ericsson has been releasing its new latest breed in mobile market known as Sony Ericsson Aino. This classy mobile comes in two classy colors that are Obsidian Black and Luminous White. This handset can remotely connect with a PS3 gaming console to stream content but more importantly allow user playing on the go. This smart phone is an outstanding multimedia and imaging mobile phone that merges the best of Cybershot technologies and Sony's Walkman. The Best thing about the handset is that now every people can easily purchase it through Sony Ericsson Aino Contract.
There are many netwo... (read more)
Author: Torie Wilson
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6. How Are Fossils Formed?
October 04, 2009
Fossils are relatively rare. Most plants and animals decay and are eventually become of the land that sustained them during their lifespan. Sometimes accidents of nature happen, however, and a fossilized footprint, leaf or even portions of a body are preserved and we are left with historical records. Here are some of the most common ways that fossils are formed: 1. Freezing. Freezing provides the most complete preservation, but it is also occurs very rarely. Temperatures must be low enough to prevent any decay and must stay that way for a sustained period of time. Remains of wooly ma... (read more)
Author: Donna Wade
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7. A Slider and Touchscreen Phone in One - the Sony Ericsson Aino
September 10, 2009
Unique features The Sony Ericsson Aino has just been announced as another remarkable mobile phone due out in Obsidian Black and Luminous White in time for Christmas 2009. It not only combines the best CyberShot and Walkman features we’ve come to expect from the company’s mid to high end mobile phones, it has a few pioneering features that make the Aino a stand out both in looks and function. • This is the first mobile phone from Sony Ericsson to have full integration with its Sony PS3 gaming console using its RemotePlay feature. Acting as a remote PS3 client, the Aino can stream a... (read more)
Author: Simon Drew
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8. Pi Yao attracts Feng Shui Fortune
September 10, 2009
Feng Shui which means “the way” has a rich past going back tens of thousands of years. It has been a great practice that has been used by many to attain god health, good health and an overall good life. Feng Shui originally came from China and in today’s world has done great wonders for the betterment of the quality of life of those who believe. Zi Wei Dou Shu on the other hand can be translated as "Purple Mild Calculation”. Since Zi Wei has reference to the Emperor star, some of the believers refer to it as Emperor Astrology. Zi Wei is the first start in the series and it is based on its pos... (read more)
Author: John Penn
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9. Ethiopian History
July 24, 2009
Ethiopia has seen human habitation for longer than almost anywhere else in the world, possibly being the location where humans evolved.
Evidence of Naqadan contacts include obsidian from Ethiopia. The first records of Ethiopia proper come from Egyptian traders from about 3000 BC, who refer to lands south of Nubia or Cush as Punt and Yam. The Ancient Egyptians were in possession of myrrh (found in Punt) as early as the First or Second Dynasties, which Richard Pankhurst interprets to indicate trade between the two countries extant from the beginning of Ancient Egypt's beginnings. J. H. Brea... (read more)
Author: Abesha Habesha
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10. BUYING BEADED JEWELLERY AS A GIFT
June 14, 2009
If you are looking for a gift, beaded jewellery is always a good choice. There are always such a great range of beaded jewellery to choose from. You can find pieces of beaded jewellery in precious metals such as gold and silver that are set with beautiful semi-precious beads like Amazonite, Fluorite, Obsidian, Jade and that beautiful semi-precious natural stone of Tigers Eye.
It maybe that this type of beaded jewellery maybe too expensive for a gift so you may decide to choose to look at beaded fashion jewellery that is more affordable like costume jewellery and imitation beaded jewellery... (read more)
Author: Kathy Drake
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11. What can Obsidian Crystal Do for You
December 22, 2008
Like all crystals there are many benefits to those who cherish their healing and comforting qualities. The Obsidian crystal is known as one of the most beautiful and beneficial stones available. There are many benefits from the Obsidian crystal and it holds a variety of Metaphysical qualities. The Obsidian Crystal which is also known as the “Stone of Truth” is a natural glass that consists of volcanic lava that has been cooled quickly. It was also one of the first stones to ever be used for a weapon such as an arrowhead or knife.
Obsidian crystal helps individuals to see flaws inside the... (read more)
Author: Silvia Blach
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12. The Last of the Obsidian Artifacts in Puerto Vallarta
September 04, 2008
By: Jim Scherrer
More than 30 years ago during one of our first visits to Puerto Vallarta, Mexico, while browsing through a small souvenir shop, we noticed a handful of small black objects high on a back corner shelf. They were covered with dust and obviously hadn’t been touched for years. We asked the owner of the tienda what they were and he indicated that they were obsidian artifacts; insinuating that they were very old and that obsidian was quite rare and virtually approaching extinction. Since this was the first time we had ever seen obsidian and being quite naïve, we thought they mi... (read more)
Author: Jim Scherrer
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13. Home Shop 18 Shopping - Online Jewellery Store
June 23, 2008
Searching for jewellery for your sister who is going for marriage? Have a look below and buy the best.
(1). Power Bracelets Model No: PB003
Features:
Obsidian is considered extremely protective and said to allow no negative energy or negative spirit to enter Benefits: Protection, Grounding & Peace
(2). D'damas Pendant GS13054
D'damas is about luxury and aspirations, bestowing upon the wearer a special status. D'damas vast variety of sub-brands allows every customer a choice of jewellery to reflect their personality, tastes and to suit every occasion. Exclusively fro... (read more)
Author: Brendon long
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14. A-Z Healing Benefits of Crystal and Stones
April 09, 2008
Agate - helps to awaken your inherent talents, increases creativity and stimulates intellectual as well as analytical abilities. This stone gives you the confidence to be the best you can be in achieving success by instilling courage and dispelling fears in the wearer. Amber - Amber absorbs negative energies and transforms them into positive forces that stimulate the body to heal itself. It can also help counteract suicidal or depressive tendencies. Amethyst - has the power to calm the mind and emotions, creating a sense of peace. Amethyst also stimulates the intellectual and creat... (read more)
Author: Jenny Lin
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15. Things to consider when purchasing granite tile
October 23, 2007
Granite is composed of several minerals such as quartz, silica, mica, obsidian and feldspar. People like to opt for granite due to its’ beauty. Slabs of granite consist of unique crystals, color variations and depth. The stone is famous world wide because it never loses its color and brilliance. Granite is the first choice for countertops in many parts of the world including countries like the US, Brazil, Canada, China, India, Norway, Sri Lanka and Italy. The cost of this stone for countertops will vary as per the square footage and many other factors including edge and backsplash select... (read more)
Author: Steve Manik
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16. Glass
March 01, 2006
History indicates that glass has been in use since the Stone Age. Around 7500 BCE glass in its natural form, obsidian, was utilized to fashion tools. Detailed descriptions on glass-blowing techniques were documented as early as 1500 BCE in Egypt. The Egyptians used glass to glaze pottery before it was fired.Natural glass is of many kinds: obsidian is glass formed by volcanic eruptions, when masses of naturally occurring silica fuse with intense heat to form glass that is hard, shiny, opaque, and either black, red, or green; tektites and Libyan desert glass are created by meteoritic impacts wit... (read more)
Author: Jason Gluckman
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