- “Bringing The Past, Into the Future”
- +44 (0) 1204 388754
PRODUCTS BY WEIGHT
BOX SETS
PLASTIC DISPLAY PRODUCTS
PRODUCTS BY WEIGHT
BOX SETS
PLASTIC DISPLAY PRODUCTS
£12.00 ex VAT
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.
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. 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.
Weight | 1100 g |
---|
|
|
0% |
|
|
0% |
|
|
0% |
|
|
0% |
|
|
0% |
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
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
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
Specimens of Limestone, collected from Derbyshire. Limestone is a common, well known sedimentary rock. It consists of the calcium-rich shells, bones, and skeletons of the fauna that dominated during that period. It was laid down approximately 350 million years ago in semi tropical seas and comes from the Dinantian epoch of the Lower Carboniferous. This rock is very pure, about 98% soluble in rainwater (over time) leaving only residual clay. Its uses include aggregate, building stone, the manufacture of cement, paper & calcium carbide. Available in various sizes, each piece comes supplied in a white card tray with information label.
We also supply Limestone thin sections for microscope study which are available to buy HERE.
100 in stock
Peridotite, found in Finland, is a dense, coarse grained igneous rock. It is commonly used in saunas due to certain porpertie. These rock specimens are ideal teaching aids or collectors specimens. Supplied in a card tray with label, offered in 3 optional sizes.
We also supply Peridotite thin sections for microscope study which are available to buy HERE.
32 in stock
Graphic granite is an igneous pegmatite rock from Iveland, Norway, which forms in intrusive batholithic bodies that have a felsic composition. As such, the rock is mainly composed of quartz and orthoclase feldspar crystals and lacks any mica, making the rock leucocratic. These samples have what is known as a graphic texture, due to the formation of the crystals, which result in an appearance similar to that of cuneiform text which was once used by ancient human cultures. A brightly coloured, eye catching rock, the samples are suitable for collectors and educational use at higher levels and come available in three sizes. Each specimens is supplied in a card tray with an information label.
91 in stock
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. Specimens are supplied in a polythene bag in lots of 1 kg with a label.
Gabbro thin section exhibiting some of the textbook features one would expect from this coarse, mafic igneous rock. These slides supplement the hand specimens nicely and are useful for interpreting the crystalisation history of the rock.
We provide a full range of igneous, sedimentary, metamorphic and mineral thin sections. Click here to view them. Should you require a microscope, they can be found here.
Out of stock
Syenite thin section slide. The thin sections show a dominant feldspar mass ( orthoclase ) with occurrences of hornblende, amphibole and clinopyroxene. Biotite mica may also be present however its occurrence is rare, The thin section is supplied in a protective card sleeve with a label, ideal for microscopy and educational purposes.
Click here to to explore our extensive collection of igneous, sedimentary, metamorphic, and mineral thin sections. We offer a wide range of options to cater to your needs. If you require a microscope, you can find them available here as well.
5 in stock
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
Gabbro igneous rock specimens from Balmedie quarry, Aberdeen, Scotland which exhibit a coars grained texture from the crystals. Formed as a mafic pluton intrusion, the samples contain pyroxenes such as augite along side plagioclase feldspar, amphibole and olivine crystals. They are derived from a body known as the Belhelvie basic intrusion which the parent unit being the Caledonian Supersuite. Samples exhibit a grey colouration and density and are suitable for the more serious or professional collector or higher educational use to differentiate similar looking igneous rocks with different compositions and origins. Available in three sizes, the specimens come supplied in a card tray with an information label.
We also supply Gabbro thin sections for microscope study which are available to buy HERE.
27 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.
Classic Gabbro specimens, showing typical coarse grained crystalline texture. Gabbro is an intrusive mafic igneous rock chemically similar to basalt.
41 in stock
Graphic Granite is a leucocratic igneous rock found predominantly in granitic pegmatites. It’s coarse intergrowths of feldspars display a Runic or Cuneiform configuration hence the term “graphic”
98 in stock
Reviews
There are no reviews yet.