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PRODUCTS BY WEIGHT
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PLASTIC DISPLAY PRODUCTS
PRODUCTS BY WEIGHT
BOX SETS
PLASTIC DISPLAY PRODUCTS
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Obsidian is a naturally occurring volcanic glass derived from a rapidly cooled high silica lava. Often associated with the margins of Rhyolitic lava flows. It has little or no discernable crystalline structure. Specimens are supplied in a polythene bag in lots of 1 kg with a label.
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Obsidian is a natural volcanic glass. An extrusive igneous rock. It is produced when silica rich lava extruded from a volcano rapidly cools minimising crystal growth. Obsidian is commonly found within the margins of rhyolitic lava flows known as obsidian flows. The high silica content (70 -75%) produces a highly viscous lava with some degree of polymerization. The inhibition of atomic diffusion through this highly viscous and polymerized lava explains the lack of crystal growth. It is classed as metastable as over time it will crystalise. Non has been found over Cretaceous in age. Obsidian is hard and brittle with a concoidal fracture it therefore breaks with very sharp edges, which were used in the past in cutting and piercing tools. It has been used experimentally as scalpel blades.
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Rhyolite Felsite, a highly felsitic composed variation of Rhyolite, found in Scotland. Specimens are supplied in a polythene bag in lots of 1 kg with a label.
This Mahogany obsidian is sourced in the United States of America. Impurities of magnesium and iron give this variety a red or brown appearance hence the name ‘mahogany obsidian’ or oak obsidian. Specimens are supplied in a polythene bag in lots of 1 kg with a label.
Out of stock
Snowflake obsidian is quite striking in appearance. It is characterised by the inclusion of radially clustered crystals of cristobalite, which when viewed at a glance, appear like snowflakes on the surface of the rock. These crystal clusters are set in an otherwise black vitreous matrix of obsidian, which is an naturally occurring volcanic glass, even exhibiting a conchoidal fracture. Cristobalite is a high temperature polymorph of silica, it can form as a result of the devitrification of the obsidian. These specimens come from Java, Indonesia and are supplied in card trays, sizes which are optional, each tray also has a small data label supplied.
We also supply Snowflake Obsidian thin sections for microscope study which are available to buy HERE.
Obsidian is an extrusive igneous rock, these specimens exhibit a typical black colouration with conchoidal fractures, they come from South East Mexico and are excellent for educational use and collectors due to the quality. This igneous rock forms when magma extrudes onto the earths surface, chemically it is silica rich and impurities give the black colouration. It’s fine crystalline texture and fracture makes obsidian appear glassy and it breaks as such. The pieces are available in various sizes and come supplied in a card tray with an information label.
We also supply Obsidian thin sections for microscope study which are available to buy HERE.
Mahogany obsidian sourced from the United States of America. Impurities of magnesium and iron give this variety a red or brown appearance hence the name ‘mahogany obsidian’ or oak obsidian. Each Sample is supplied in a labelled card tray.
Out of stock
Classic Gabbro specimens, showing typical coarse grained crystalline texture. Gabbro is an intrusive mafic igneous rock chemically similar to basalt.
41 in stock
Metagabbro specimens from Lom, Central Norway. Also known as scapolite-hornblende due to the absence of feldspar in the rock are available in 3 optional sizes and come supplied in a card tray with a data label.
40 in stock
Larvikite is an igneous plutonic rock and variant of monzonite from Larvik, Norway, due to its chemistry, it is composed mainly of orthoclase, albite and anorthite along with plagioclase which gives the rock a blue to silver shimmering effect. The igneous pluton formed during the Permian period, 292 – 298 million years ago during the the Variscan orogeny. A beautiful rock to observe due to its coarse crystalline texture and schiller effect, the samples are ideal for general interest, collectors and educational use with specimens being available in three sizes and come supplied in a card tray with an information label.
We also supply Syenite thin sections for microscope study which are available to buy HERE.
138 in stock
Rhyolite specimens found in Cumbria. Rhyolite is a felsic (silica rich) rock, often formed in highly explosive volcanoes. Specimens are supplied in a polythene bag in lots of 1 kg with a label.
Rhyolite thin section slide exhibiting the fine grained nature of this felsic igneous rock. The thin section shows a silica rich mineral assemblage of fine grained quartz and plagioclase. Accessory minerals present include biotite mica and hornblende. This material was collected from Cumbria, UK.
7 in stock
This granite pegmatite contains large sheets of muscovite mica, orthoclase feldspar and quartz matrix. An excellent teaching material which comes from Southern Norway. Each specimen comes in a labelled card tray.
Out of stock
Pumice specimens from the Lipari islands, Italy. Pumice is an igneous rock with a highly porous structure resulting from trapped gas bubbles as the lava was being ejected. The rock is usually very light & buoyant in water. Specimens are supplied in a card tray with label.
We also supply Pumice thin sections for microscope study which are available to buy HERE.
49 in stock
Stunning peridotite thin section exhibiting the bright and beautiful colours of olivine and pyroxene punctuated by relatively abundant plagioclase. Peridotite is a dense, coarse grained, ultramafic igneous rock consisting largely of olivine and pyroxene.
7 in stock
Greisen metamorphic rock specimens from Caldbeck Fells, Cumbria, composed mainly of quartz and mica with an off yellow colouration. The rock is known as an endoskarn and forms when hydrothermal fluid and heat alter a granitic body, resulting a heavily altered rock which may contain trace amounts of rare elements. These samples are suitable for advanced collectors and higher level education and are available in three sizes, each pieces will come supplied in a card tray with a label.
We also supply Greisen thin sections for microscope study which are available to buy HERE.
18 in stock
Pumice thin section slide exhibiting the highly vesicular nature of this extrusive igneous rock. Pumice lavas tend to be silicic or felsic which are highly viscous thus do not allow the gas bubbles to escape efficiently.This material was collected from the Lipari islands of Italy.
9 in stock
Obsidian, also known as ‘volcanic glass’ is a felsic, extrusive igneous rock. Crystal growth is minimal / absent within obsidian due to rapid solidification rates which inhibit crystal growth thus giving the rock a glassy appearance.
4 in stock
Shap granite igneous rock specimens from Shap Fell, Cumbria, UK which exhibit typical coarse grained crystalline textures expected of intrusive felsic rocks, being composed of quartz, plagioclase and orthoclase feldspar and biotite mica. This popular granite is very sought after for a variety of applications and has a colourful appearance. It is believed to have formed during the early Devonian period as a plutonic intrusion in the area and is quarried extensively. Samples are ideal for collectors of all levels and ages as well as all educational levels as the minerals can be easily described with the origin and processes being suitable to teach higher level students. Samples are available in three sizes and come supplied in a card tray with an information label.
We also supply Shap Granite thin sections for microscope study which are available to buy HERE.
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