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Title: Mookite Jasper
Medium: Digital Photography
Photographer: Aaron J. Greenblatt
Camera Type: Panasonic DMC-LZ7 Lumix 7.2 MP
Editing: Edited in PhotoShop 7.0 for color accuracy, size, and to apply copyright and border.
Location: Photograph taken at the 2008 Southeastern Michigan Gem and Mineral Show at the Southgate Civic Center in Southgate, Michigan. Show hosted by the Midwest Mineralogical & Lapidary Society.
Description: This 12-inch-wide piece of Mookite Jasper is from Australia. It was sitting behind a dealer's table up on a shelf and was priced to sell at a hefty $135. This specimen had been slabbed (cut into a thin section) and polished from a much larger piece. The white spots are light reflections from the bright ubiquitous lights used to provide illumination at the show. The red coloration in this material is caused by iron.
About Mookite Jasper: According to some dealers, "Mookaite" is considered the correct spelling for the name of this jasper. This is because it is named after the local area it comes from, Mooka Creek in the Kennedy Ranges near Gascoyne Junction (which is about 100 miles inland from the coastal town of Carnarvon) in Western Australia. However, the above piece was tagged as Mookite by the dealer selling it.
According to mindat - The term 'Mookaite' is an unofficial, locally coined name for a silicified porcelanite which forms in the weathering profile of a geological formation known as Windalia Radiolarite (WR), a Lower Cretaceous siltstone that outcrops over much of the Carnarvon Basin in Western Australia.
In more laymen terms, Mookite Jasper is a fossiliferous sedimentary rock. In this jasper it is reasonably common to find cavities left by decomposed belemnite casts or in some rare cases, impressions of ammonites. Belemnites are an extinct group of marine cephalopod related to the common squid and cuttlefish.
Microscopic examination of Mookite Jasper shows this rock also consists of the remains of tiny organisms known as radiolaria that have an unusual skeletal structure of opaline silica. Billions of these little critters were deposited as sediment in the shallow areas of ancient sea beds. When the seas retreated, these sediments were cemented into solid rock by silica carried in groundwater. The type and degree of silicification varies from place to place, forming opalite, chert and chalcedony.
About Jasper: Jasper is a variety of quartz - an opaque, impure silica, usually red, yellow, brown or green in color. Jasper breaks with a smooth surface, and is used for ornamentation or as a gemstone. It has a hardness of 7 so it wears well and polishes to a high shine.
About Jasper Naming:The classification and naming of jasper presents an enormous challenge. Terms attributed to various well-defined jasper materials often include the geographical locality where the jasper is found. These geographical names are sometimes quite restricted - such as "Bruneau" (a canyon) and "Lahontan" (a lake), rivers and even individual mountains.
Many jasper names are fanciful such as "Forest Fire" or "Rainbow", while others are descriptive such as "Autumn", "Porcelain" or "Dalmatian". A few are designated by the country of origin such as "Brown Egyptian" or "Red African" - leaving tremendous latitude as to what types are called what names. Then there are inappropriately named materials, for example "Ocean Jasper" from Madagascar which is really a chalcedony, as is Bloodstone from India.
Information Sources:
[link] (topgems - Mookite Information)
[link] (mindat - Mookaite)
[link] (mindat - Jasper)
[link] (wiki - Jasper)
[link] (wiki - Belemnite)
Legal: Copyright © Aaron J. Greenblatt. All rights reserved. Commercial use prohibited. This image and commentary may not be used for any reason without expressed written consent.
Please click here to view my photography work located in my Gallery.
Please click here for images of my glass work located in my other Gallery.
Please click here for images of my glass studio located in my other Scraps.
Title: Mookite Jasper
Medium: Digital Photography
Photographer: Aaron J. Greenblatt
Camera Type: Panasonic DMC-LZ7 Lumix 7.2 MP
Editing: Edited in PhotoShop 7.0 for color accuracy, size, and to apply copyright and border.
Location: Photograph taken at the 2008 Southeastern Michigan Gem and Mineral Show at the Southgate Civic Center in Southgate, Michigan. Show hosted by the Midwest Mineralogical & Lapidary Society.
Description: This 12-inch-wide piece of Mookite Jasper is from Australia. It was sitting behind a dealer's table up on a shelf and was priced to sell at a hefty $135. This specimen had been slabbed (cut into a thin section) and polished from a much larger piece. The white spots are light reflections from the bright ubiquitous lights used to provide illumination at the show. The red coloration in this material is caused by iron.
About Mookite Jasper: According to some dealers, "Mookaite" is considered the correct spelling for the name of this jasper. This is because it is named after the local area it comes from, Mooka Creek in the Kennedy Ranges near Gascoyne Junction (which is about 100 miles inland from the coastal town of Carnarvon) in Western Australia. However, the above piece was tagged as Mookite by the dealer selling it.
According to mindat - The term 'Mookaite' is an unofficial, locally coined name for a silicified porcelanite which forms in the weathering profile of a geological formation known as Windalia Radiolarite (WR), a Lower Cretaceous siltstone that outcrops over much of the Carnarvon Basin in Western Australia.
In more laymen terms, Mookite Jasper is a fossiliferous sedimentary rock. In this jasper it is reasonably common to find cavities left by decomposed belemnite casts or in some rare cases, impressions of ammonites. Belemnites are an extinct group of marine cephalopod related to the common squid and cuttlefish.
Microscopic examination of Mookite Jasper shows this rock also consists of the remains of tiny organisms known as radiolaria that have an unusual skeletal structure of opaline silica. Billions of these little critters were deposited as sediment in the shallow areas of ancient sea beds. When the seas retreated, these sediments were cemented into solid rock by silica carried in groundwater. The type and degree of silicification varies from place to place, forming opalite, chert and chalcedony.
About Jasper: Jasper is a variety of quartz - an opaque, impure silica, usually red, yellow, brown or green in color. Jasper breaks with a smooth surface, and is used for ornamentation or as a gemstone. It has a hardness of 7 so it wears well and polishes to a high shine.
About Jasper Naming:The classification and naming of jasper presents an enormous challenge. Terms attributed to various well-defined jasper materials often include the geographical locality where the jasper is found. These geographical names are sometimes quite restricted - such as "Bruneau" (a canyon) and "Lahontan" (a lake), rivers and even individual mountains.
Many jasper names are fanciful such as "Forest Fire" or "Rainbow", while others are descriptive such as "Autumn", "Porcelain" or "Dalmatian". A few are designated by the country of origin such as "Brown Egyptian" or "Red African" - leaving tremendous latitude as to what types are called what names. Then there are inappropriately named materials, for example "Ocean Jasper" from Madagascar which is really a chalcedony, as is Bloodstone from India.
Information Sources:
[link] (topgems - Mookite Information)
[link] (mindat - Mookaite)
[link] (mindat - Jasper)
[link] (wiki - Jasper)
[link] (wiki - Belemnite)
Legal: Copyright © Aaron J. Greenblatt. All rights reserved. Commercial use prohibited. This image and commentary may not be used for any reason without expressed written consent.
Please click here to view my photography work located in my Gallery.
Please click here for images of my glass work located in my other Gallery.
Please click here for images of my glass studio located in my other Scraps.
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Comments15
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I was at East borgafjord 2 years ago and saw a huge jasper that was at least 100+ kilos and larger than this one.