Epidote from Slovakia

Epidote is a calcium aluminium iron sorosilicate mineral, Ca₂(Al, Fe)₃(SiO₄)₃(OH), crystallizing in the monoclinic system. Well-developed crystals are of frequent occurrence: they are commonly prismatic in habit, the direction of elongation being perpendicular to the single plane of symmetry. The faces are often deeply striated and crystals are often twinned. Many of the characters of the mineral vary with the amount of iron present for instance, the color, the optical constants, and the specific gravity (3.33). The hardness is 6.5. The color is green, grey, brown or nearly black, but usually a characteristic shade of yellowish-green or pistachio-green. The pleochroism is strong, the pleochroic colors being usually green, yellow and brown. Clinozoisite is white or pale rose-red variety containing very little iron, thus having the same chemical composition as the orthorhombic mineral zoisite. Image File history File links Mineraly. ... Image File history File links Mineraly. ... General Name, Symbol, Number calcium, Ca, 20 Chemical series alkaline earth metals Group, Period, Block 2, 4, s Appearance silvery white Atomic mass 40. ... This article or section contains information that has not been verified and thus might not be reliable. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ... The silicate minerals make up the the largest and most important class of rock-forming minerals. ... Minerals are natural compounds formed through geological processes. ... It has been suggested that crystallization processes be merged into this article or section. ... In crystallography, the monoclinic crystal system is one of the 7 lattice point groups. ... Clinozoisite is a mineral, a complex silicate of calcium and Aluminium, formula, Ca2Al3(O,OH,SiO4, Si2O7). ... In crystallography, the orthorhombic crystal system is one of the 7 lattice point groups. ... Zoisite is a calcium aluminium hydroxy sorosilicate belonging to the epidote group of minerals. ...

Epidote is an abundant rock-forming mineral, but one of secondary origin. It occurs in crystalline limestones and schistose rocks of metamorphic origin. It is also a product of hydrothermal alteration of various minerals (feldspars, micas, pyroxenes, amphiboles, garnets, and others) composing igneous rocks. A rock composed of quartz and epidote is known as epidosite. Well-developed crystals are found at many localities: Knappenwand, near the Großvenediger in the Untersulzbachthal in Salzburg, as magnificent, dark green crystals of long prismatic habit in cavities in epidote schist, with asbestos, adularia, calcite, and apatite; the Ala valley and Traversella in Piedmont; Arendal in Norway; Le Bourg doisans in Dauphin; Haddam in Connecticut; Prince of Wales Island in Alaska, here as large, dark green, tabular crystals with copper ores in metamorphosed limestone. Limey shale overlaid by limestone. ... Schist The schists form a group of medium-grade metamorphic rocks, chiefly notable for the preponderance of lamellar minerals such as micas, chlorite, talc, hornblende, graphite, and others. ... Metamorphic rock is the result of the transformation of a pre-existing rock type, the protolith, in a process called metamorphism, which means change in form (from the Greek prefix meta, after, and the noun morphe, form). The protolith is subjected to heat (greater than 150 degrees Celsius) and extreme... Hydrothermal circulation in the oceans is the passage of the water through mid-ocean Ridge (MOR) systems. ... Feldspar is the name of an important group of rock-forming minerals which make up perhaps as much as 60% of the Earths crust. ... rock with mica Mica sheet mica flakes The mica group of minerals includes several closely related materials having highly perfect basal cleavage. ... Figure 1:Mantle-peridotite xenolith with green peridot olivine and black pyroxene crystals from San Carlos Indian Reservation, Gila Co. ... For the logical fallacy, see Amphibology. ... The garnet group of minerals show crystals with a habit of rhombic dodecahedrons and trapezohedrons. ... Igneous rocks are formed when molten rock (magma) cools and solidifies, with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks. ... Quartz is amongst one of the most common minerals in the Earths continental crust. ... Epidosite is a highly altered epidote and quartz bearing rock. ... Großvenediger is generally considered to be Austrias third highest mountain (although it can be up to sixteenth if every subsidiary summit is counted). ... Fibrous asbestos on muscovite Asbestos Asbestos Asbestos (a misapplication of Latin: asbestos quicklime from Greek ἄσβεστος: a-, not; sbestos, extinguishable) describes any of a group of fibrous metamorphic minerals of the hydrous magnesium silicate variety. ... Adularia is a tectosilicate mineral with formula KALSi3O8. ... SAM WAS HERE!!!!!!!!!! Doubly refracting Calcite from Iceberg claim, Dixon, New Mexico. ... Apatite is a group of phosphate minerals, usually referring to: hydroxylapatite, fluorapatite, and chlorapatite, named for high concentrations of OH-, F-, or Cl- ions, respectively, in the crystal lattice. ... This article or section does not cite its references or sources. ... Official language(s) English Capital Largest city Juneau Anchorage Area  - Total   - Width   - Length    - % water  - Latitude  - Longitude Ranked 1st 663,267 sq mi  1,717,854 km² 808 miles  1,300 km 1,479 miles  2,380 km 13. ... General Name, Symbol, Number copper, Cu, 29 Chemical series transition metals Group, Period, Block 11, 4, d Appearance metallic brown Atomic mass 63. ... Iron ore (Banded iron formation) Manganese ore Lead ore Gold ore An ore is a volume of rock containing components or minerals in a mode of occurrence which renders it valuable for mining. ...

The perfectly transparent, dark green crystals from the Knappenwand and from Brazil have occasionally been cut as gemstones.

Belonging to the same isomorphous group with epidote are the species piemontite and allanite, which may be described as manganese and cerium epidotes respectively. Allanite is a silicate containing a large amount of cerium. ... General Name, Symbol, Number manganese, Mn, 25 Chemical series transition metals Group, Period, Block 7, 4, d Appearance silvery metallic Atomic mass 54. ... General Name, Symbol, Number cerium, Ce, 58 Chemical series lanthanides Group, Period, Block n/a, 6, f Appearance silvery white Atomic mass 140. ...

Piemontite occurs as small, reddish-black, monoclinic crystals in the manganese mines at San Marcel, near Ivrea in Piedmont, and in crystalline schists at several places in Japan. The purple color of the Egyptian porfido rosso antico is due to the presence of this mineral.

Allanite has the same general epidote formula and contains metals of the cerium group. In external appearance it differs widely from epidote, being black or dark brown in color, pitchy in lustre, and opaque in the mass; further, there is little or no cleavage, and well-developed crystals are rare. The crystallographic and optical characters are similar to those of epidote; the pleochroism is strong with reddish-, yellowish-, and greenish-brown colors. Although not a common mineral, allanite is of fairly wide distribution as a primary accessory constituent of many crystalline rocks, gneiss, granite, syenite, rhyolite, andesite, and others. It was first found in the granite of east Greenland and described by Thomas Allan in 1808, after whom the species was named. Allanite is a mineral readily altered by hydration, becoming optically isotropic and amorphous: for this reason several varieties have been distinguished, and many different names applied. Orthite was the name given by Jöns Berzelius in 1818 to a hydrated form found as slender prismatic crystals, sometimes a foot in length, at Finbo, near Falun in Sweden. Gneiss Gneiss is a common and widely distributed type of rock formed by high grade regional metamorphic processes from preexisting formations that were originally either igneous or sedimentary rocks. ... Quarrying granite for the Mormon Temple, Utah Territory. ... Syenite Syenite is a coarse-grained intrusive igneous rock of the same general composition as granite but with the quartz either absent or present in relatively small amounts. ... Rhyolite Rhyolite is an igneous, volcanic (extrusive) rock, of felsic composition, with aphanitic to porphyritic texture. ... A sample of andesite (dark groundmass) with amygdaloidal vesicules filled with zeolite. ... 1808 was a leap year starting on Friday (see link for calendar). ... An amorphous solid is a solid in which there is no long-range order of the positions of the atoms. ... Jöns Jakob Berzelius (August 20, 1779 - August 7, 1848) was a Swedish chemist, who invented modern chemical notation and is considered one of the fathers of modern chemistry (along with John Dalton and Antoine Lavoisier). ... 1818 (MDCCCXVIII) is a common year starting on Thursday of the Gregorian calendar or a common year starting on Saturday of the 12-day slower Julian calendar. ...

References

• This article incorporates text from the Encyclopædia Britannica Eleventh Edition, a publication now in the public domain.

Encyclopædia Britannica, the 11th edition The Encyclopædia Britannica Eleventh Edition (1910–1911) is perhaps the most famous edition of the Encyclopædia Britannica. ... The public domain comprises the body of all creative works and other knowledge—writing, artwork, music, science, inventions, and others—in which no person or organization has any proprietary interest. ...

External link

• The mineral Epidote Mineral Galleries