- “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
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.
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
Greisen are metamorphic rocks formed by hydrothermal alteration of felsic igneous rocks such as granites or pegmatites. As such, they are mostly composed of micas and quartz mienerals but little to no feldspar and can be more clearly defined as an endoskarn. This process occurs when a granitic pluton releases heat and hydrothermal fluids as a later stage which results in a process known as greisenisation, altering the pre-existing granite already in place. Essentially, the granitic intrusion metamorphosed its self. The rock its self has a coarse grained texture with crystals being easily visible with the naked eye, similar to granites naturally, however, they tend to have an overall yellow colouration due to processes that led to the formation which leave the rock not very attractive to look at. But the unique process in which greisen forms does result in rare elements crystallising within the endoskarn which are often of high economic value, these include fluorites, wolframite, cassiterite, lepidolite mica and many more, thus making greisen bodies an excellent source of rare metals in the past and as an indicator to potential ore deposits in a particular area. These particular samples come from the Caldbeck Fells in Cumbria and are ideal for advanced collectors or those interest in rare metals and their associated rock formations, as well as higher level education to describe altered bodies of rock and the potential to find ore deposits in the area. The specimens are available in three sizes and come supplied in a card tray with an information label.
We also supply Greisen 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" |
|
|
0% |
|
|
0% |
|
|
0% |
|
|
0% |
|
|
0% |
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
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.
31 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
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
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
Specimens of Aeolian Sandstone collected from Lazonby, near Penrith, Cumbria in the UK. This aeolian sandstone is Triassic in age – approximately 200 Ma. It belongs to the group of rocks known as the New Red Sandstone which date from the Permian (280 Ma) into the Triassic. The composition of this sandstone consists solely of spheroidal (millet seed) quartz grains with an iron oxide cement called haematite. It is the presence of this haematite that contributes to the distinct red – orange colouration of these samples. This lithology is typical of an aeolian (wind blown) hot desert environment. Available in multiple sizes, these specimens come supplied in a white card tray with information label.
We also supply Aeolian Sandstone 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.
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.
66 in stock
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
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
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
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.
Reviews
There are no reviews yet.