- “Bringing The Past, Into the Future”
- +44 (0) 1204 388754
£1.38 – £3.46 ex VAT
Tuff from the Borrowdale Volcanic Group, Ordovician in age, the rock has a green colouration to it and a slate like cleavage, hence sometimes being known as volcanic slate, green slate or Borrowdale slate. Rock specimens are available in 3 optional sizes and will come supplied in a card tray 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
Volcanic tuff is an igenous rock, more specifically, belonging to the pyroclastic group. Pyroclastic rocks are essentially composed almost all from volcanic material although sometimes, inclusions of country rock (the surrounding rock which was already in place) can be seen. Volcanic tuff is formed from phreatomagmatic eruptions, where volcanic material such as ash and pyroclastic bombs are ejected from the volcano during eruptions. Tuff is essentially derived from the ash which has been ejected out of the volcano during activity, originally a fine grained ash, as the ash settled, over time through various geological processes, the ash consolidates into a solid rock which geologists know as tuff. This particular variant of tuff is green in colour due to the presence of chlorite, this particular tuff also has a slatey cleavage, meaning it breaks in slabs or slices, very similar to slate and is in fact also known as Borrowdale slate, green slate or volcanic slate. It comes from the Borrowdale valley in Cumbria, an area rich in volcanic history, the valley itsself is actually named after the Borrowdale Volcanic Group, which is comprised of a series of various volcanic rocks which formed during the Ordovician period. Specimens are available in various optional sizes and come in a card tray with a label.
Weight | 130 g |
---|---|
Specimen Size | 2" x 2", 3" x 2", 4" x 3" |
|
|
0% |
|
|
0% |
|
|
0% |
|
|
0% |
|
|
0% |
Volcanic tuff thin section exhibiting welded angular clasts of varying size. A degree of orientation can be identified as a result of the fallout of volcanic ejecta. Each section is made to 30 microns thickness and the glass is 46 x 27 mm in size with a cover slip.
4 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.
69 in stock
A variation of gabbro, Troctolite consists of olivine and plagioclase along with small amounts of pyroxene. It is a coarsed grained rock and are supplied in a 2″ x 2″ white card tray.
Out of 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. They are supplied in a small white tray with an information label.
197 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.
2 in stock
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.
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.
75 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.
76 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.
95 in stock
Essexite igneous rock specimens from Lanarkshire, Scotland, UK, also known as olivine or nepheline monzogabbro is an intrusive rock with mafic chemistry, composed of nepheline and plagioclase feldspar along with olivine, magnetite minerals as well as augite phenocrysts which exhibit euhedral crystal forms. The rock has a dense weight and overall dark colouration but attractive appearance. It is locally known as Crawfordjohns and was highly sought after as a high quality material to produce curling stones. These samples are excellent for young and older collectors as well as higher educational use, the pieces are available in three sizes and come supplied in a card tray with an information label.
63 in stock
An igneous rock exhibiting a porphyritic texture containing large cubic crystals of feldspar within a fine grained matrix. Collected near Oslo, Norway. Each sample is supplied in a labelled card tray. Each sample is supplied in a labelled card tray.
58 in stock
Olivine dolerite igneous rock specimens from Clee Hill, Shropshire, UK, composed of pyroxene minerals such as augite and magnetite as well as plagioclase feldspar. The samples are fine grained and crystalline in texture with a dense weight and black colouration. Similar in appearance to gabbro and basalt, the rock samples are suitable for serious collectors or higher level education to explain the difference in chemistry and mineralogy of igneous rocks. The samples are available in three sizes and supplied in a card tray with an information label.
70 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.
80 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.
44 in stock
Reviews
There are no reviews yet.