- “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% |
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
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.
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.
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.
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
Banded rhyolite from Glen Coe, Scotland showing laminar flow banding which was produced by the viscous lava which formed the rock, available in various sizes, these specimens are suitable for educational use to display flow banding. Supplied in a card tray with an information label.
65 in 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
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
Big feldspar gabbro thin section exhibiting exactly what its name describes, feldspar crystals much larger than those present in the ordinary gabbro which we supply. Characteristic twinning in the plagioclase and the bright colours of the pyroxene make for an attractive thin section, perfect for educational use.
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.
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
Granite adamellite thin section slide exhibiting crystals of quartz, biotite and feldspar. We collected this material from the famous Shap Fell quarry, in Cumbria hence the rocks alternative name ‘ Shap Granite ‘.
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.
8 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
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
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
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
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.
Adamellite granite also known as shap granite from Cumbria, famous for its large pink feldspar crystals his granite is well known. The samples come from the Shap Quarry, Shap Fell, Cumbria and are supplied in a polythene bag in lots of 1 kg with a label.
Reviews
There are no reviews yet.