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PRODUCTS BY WEIGHT
BOX SETS
PLASTIC DISPLAY PRODUCTS
PRODUCTS BY WEIGHT
BOX SETS
PLASTIC DISPLAY PRODUCTS
£2.25 – £6.00 ex VAT
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.
We ship to all 50 states, Washington DC.
All orders are shipped with a UPS tracking number.
Always free shipping for orders over US $200.
During sale periods and promotions the delivery time may be longer than normal.
Elessi will accept exchanges and returns of unworn and unwashed garments within 30 days of the date of purchase (14 days during the sales period), on presentation of the original till receipt at any store where the corresponding collection is available within the country of purchase.
Your return will usually be processed within a week to a week and a half. We’ll send you a Return Notification email to notify you once the return has been completed.
Please allow 1-3 business days for refunds to be received to the original form of payment once the return has been processed.
Give us a shout if you have any other questions and/or concerns.
Email: contact@mydomain.com
Phone: +1 (23) 456 789
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 which gives the rock a fine, glassy texture. It is commonly found within the margins of rhyolitic lava flows known as obsidian flows, its 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 hard and brittle rock with a black appearance due to the presence of conchoidal fractures, it therefore breaks with very sharp edges. It is this particular feature which has made obsidian an important rock in human history and evolution and why it is so well known and popular, as the sharp edges allowed it to be used in the past in cutting and piercing tools, most notably, arrow and spear heads. It has been used experimentally as scalpel blades in the past and recent years. These particular samples come from South East Mexico, the pieces will display typical black colouration and conchoidal fractures, making them suitable for both collectors, enthusiasts and educational use. Each sample will 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.
Weight | 130 g |
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Specimen Size | 2" x 2", 3" x 2", 4" x 3", Thin Section Slide |
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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
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
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.
Micro Granite is a variation of the granite group of rocks, composed of the minerals quartz, feldspar and mica. These particular samples were collected from Threlkeld quarry, Cumbria, UK. They are supplied in a small white tray with an information label.
We also supply Microgranite thin sections for microscope study which are available to buy HERE.
193 in stock
Rhyolite Felsite, a highly felsitic composed variation of Rhyolite, found in Fife, Scotland, an extrusive igneous rock composed of sodium, quartz and feldspar, thus often having a pale white to pink colouration. Available in various sizes and supplied in a card tray with an information label.
32 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 card tray with label.
We also supply Rhyolite thin sections for microscope study which are available to buy HERE.
57 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.
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
Hand size specimens of the big feldspar variant of gabbro, samples were collected from Carrock fell, Cumbria, UK and can be supplied in 3 sizes.
We also supply Gabbro Big Feldspar thin sections for microscope study which are available to buy HERE.
66 in stock
Ignimbirte welded tuff is a pyroclastic rock of any origin formed through volcanic processes, the rock appears to show streaks of welded material on some surfaces and appears to be rhyolitic on the inside. Specimens come from Cumbria and are available in various sizes.
We also supply Welded Tuff thin sections for microscope study which are available to buy HERE.
74 in stock
Biotite granite from Spain exhibiting plagioclase feldspar, quartz and biotite mica, specimens have been cut and polished on one surface allowing easy viewing of the crystals without the aid of magnification.
2 in stock
Amygdaloidal basalt is an igneous rock which is extrusive in nature, these specimens formed over 60 million years ago during the Tertiary period and come from Ireland. They are part of the Antrim lava group and exhibit a dark colouration with occurrences of amygdales containing quartz and calcite crystals. As a basalt they are somewhat dense, but lighter than pure samples due to the cavities within them which formed as a result of gaseous activity during their ejection. Over time, hydrothermal fluids pass through the rock and minerals form within the cavities, which gives the usually dark coloured rock a speckled appearance. These samples are available in various sizes and are suitable for higher educational use to detail the subtle differences between similar igneous rocks, they come supplied in a card tray with an information label.
60 in stock
Phonolite igneous rock specimens, an intrusive crystalline version of nepheline syenite, this rock lies between felsic and mafic composition, collected from Traprain Law, Soctland, the name of the rock is derived from the ancient Greek word which means ‘sounding stone’. Which alludes to the feature this rock has of emitting a metallic ringing when struck. Samples are available in various sizes and come supplied in a card tray with a label.
46 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
Pink granite rock specimens from China, containing the expected granite minerals, however, these specimens are higher in biotite mica, thus making the pieces seem darker than other pink granites.
86 in stock
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