- “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
£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 |
---|---|
Specimen Size | 2" x 2", 3" x 2", 4" x 3", Thin Section Slide |
|
|
0% |
|
|
0% |
|
|
0% |
|
|
0% |
|
|
0% |
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.
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
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
Bytownite basalt ( Bytownite feldspar) is another variation of the common Basalt rock. Basalt tends to to be a dark, fine, crystalline igneous rock and has a number of different variations. Bytownite feldspar is a calcium rich member of the Plagioclase family. The mineral was first described in 1835 & named for Bytown (now Ottowa) where it was found in Canada. High quality transparent examples are used to make faceted stone in the jewelllery trade. In these examples the phenocrysts are green & opaque & set in a basalt matrix. The specimens come from Cumbria, UK and are supplied in a white card tray with a label.
We also supply Bytownite Basalt thin sections for microscope study which are available to buy HERE.
189 in 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
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
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.
73 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
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
Accretionary lapilli tuff is an igneous pyroclastic rock, these samples come from Longsleddle, Cumbria in the UK and forms when hot ash and debris is ejected from as volcano. Some of this material is held together by moisture and once heavy enough, falls into the ash below forming small ‘spots’ within the material, creating a speckled rock. The samples are suitable both for young and serious collectors as well as educational use and are supplied in various sizes with a card tray and label.
65 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
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
Diorite rock specimens from Cockermouth, Cumbria, is an intrusive igneous rock from the Ordovician period with a coarse, phaneratic texture composed of plagioclase feldspar, biotite mica as well as hornblende with intermediate chemistry. Found with the Skiddaw group, the rock samples are more suited for serious collectors and higher level education to describe the chemistry and mineralogy of various igneous groups. Available in 3 sizes and supplied in a card tray with an information label.
We also supply Diorite thin sections for microscope study which are available to buy HERE.
73 in stock
Reviews
There are no reviews yet.