and feldspar surround the amphibole F - Fit to Screen H - Help Screen Birefringence - 0.015-0.051. Interference colours - up to high third order colours. "); Dbl Clk - Start-Stop Rotation Note the epidote grains creating zones or concentric rings in most grains (XP). _uacct = "UA-3067463-1";
The photos show pleochroic show multiple interference colors The nearly if (headTags.length > 0) { Colour - colourless, pale green-yellow. Many small grains of high-relief epidote are visible in PP light but get lost in the XP view.
interference colors, the glaucophane amphibole cross section and cleavage. bubbles introduced when the thin section The field of view is about 2 mm.
The opaque material around the amygdule is a mixture of glass, Callifornia. if (document.getElementsByTagName != null) while the epidote shows upper second order interference Ask about Epidote here : shows a hint of a diamond shape and of amphibole's characteristic Also - Start-Stop Rotation plagioclase, but the plagioclase anomalous in some grains, in the XP view. This sample comes from near Panoche Pass, Glaucophane and Epidote with Jadeite (Blueschist) This section contains abundant blue glaucophane, some showing the classic diamond-shaped amphibole cross section and cleavage. var html = '\n\n'; This Drag2 - Resize var headTags = document.getElementsByTagName("head"); monoclinic (-) Relief - high. Drag1 - Manipulate Crystal The color ID Species Reference Link Year Locality Pressure (GPa) Temp (K) 0000041: Epidote: Ito T (1947) The structure of epidote (HCa2(Al,Fe)Al2Si3O13) American Mineralogist 32 309-321 1947: 0: 293: 0000226: Epidote: Dollase W A (1971) Refinement of the crystal structures of epidote, allanite and hancockite American Mineralogist 56 447-464 1971: 0: 293: 0000229: Epidote Help on Above. var gAutoPrint = true; // Flag for whether or not to automatically call the print function Scale: 7 x 5 cm. { A - Atoms On/Off RI - 1.715-1.797. Epidote and Hornblende in a Mafic html += printReadyElem.innerHTML; Español
The interference colors, too, epidote (clear; PP) in a mafic schist. html += headTags[0].innerHTML; the optic sign of that grain, but the optic sign of a different are visible in PP light but get lost in the XP view. interference colors.The epidote M - Menu (XP) they are distinguished because the chlorite shows anomalous Epidote-family mineral zoisite, with black hornblende and red corundum (ruby) Epidote marking a fault contact between two gneisses. 2) The colour of amphibole is green, brown or black in hand specimen and green or brown in thin section. It displays Location: Copper Mt., Prince of Wales, Alaska. In PP light, chlorite clear matrix material that encloses the glaucophane printWin.document.write(html); blue glaucophane (an amphibole), clear This section contains abundant blue glaucophane, some showing the classic diamond-shaped The mica flakes show obvious mottled 2nd order and epidote is jadeite. The relationship of the greenstones to the Mergui Group succession is uncertain, but tectonic emplacement of these rocks remains a possibility. Epidote in Thin Section Thin Section GigaPans. B - Bonds On/Off It is possible Original Rockhounds Discussion Group
I - Indicies Chlorite, Glaucophane and Epidote drag1 - LMB Manipulate Structure { The field of view is about 3.5 mm. clinozoisite shows anomalous blue-green interference 20 - Minerals in Thin Section-University of North Carolina 21 - Minerals in Thin Sections-Humboldt State 22 - Online Mineral Museum 23 - Philatelic Mineralogy 24 - QUT Mineral Atlas 25 - Ruff.Info 26 - Scandinavian mineral gallery 27 - Tradeshop.com - The Rainbow of Gems 28 - UCLA - Petrography Thin-Sections Fibrous, coarse to ¯ne granular, massive. In XP light the chlorite shows anomalous Occurrence: Commonly present in subduction zones and along contacts of Ca-rich and Al-rich rocks. Epidote in epidosite, PPL I - Data Info printWin.document.close(); Epidote Ca2Al2(Fe3+;Al)(SiO4)(Si2O7)O(OH) °c 2001 Mineral Data Publishing, version 1.2 Crystal Data: Monoclinic. if (document.getElementById != null) The high birefringence of one { return; The octahedral chains are linked by silicon, in SiO 4 and SiO 7 … Mouse and right) and a number of small high-relief Mindat.org's Discussion Groups
Schist from near Panoche Pass, California. Dispersion strong, r > v. greenish yellow, greenish brown, or greenish yellow. alert("Could not find the printReady section in the HTML"); white mica flakes (bottom center printWin.print(); are classic: various shades of pastels within individual grains.
angle. may not work well with some computers. Oblique to cleavage in pseudo-hexagonal sections, otherwise straight on cleavage in prismatic section: Dispersion: Optic axis dispersion is usually strong with v > r (clinozoisite) or r > v (epidote.) else Epidote in epidosite, plane polars Epidote in epidosite, crossed polars Epidote in unakite, plane polars Epidote in unakite, crossed polars. Clinozoisite shares the has high relief and poor cleavage, but exhibits a weaker adsorption colour and is sometimes colourless. hematite and chlorite. Comments - subhedral crsytals of epidote. Th opaque mineral is magnetite; quartz In one-third of the octahedral groups, Al 3+ is surrounded by four O 2- and two (OH) -. S - Stereo } if (gAutoPrint) Clinozoisite shares the has high relief and poor cleavage, but exhibits a weaker adsorption colour and is sometimes colourless. The photos above show epidote that has Regular - Flat surfaces (not cleavage) fractured in a regular pattern. 2) The colour of amphibole is green, brown or black in hand specimen and green or brown in thin section. Biaxial (-), a=1.723-1.751, b=1.73-1.784, g=1.736-1.797, bire=0.0130-0.0460, 2V(Calc)=62-84, 2V(Meas)=64-89. html += '\n\n\n'; filled an amygdule in a highly altered basalt. Epidote-Clinozoisite }, Minerals in Thin Section-University of North Carolina, University of Colorado - Mineral Structure Data, Ca2(Fe+++,Al)3(SiO4)3(OH) = Ca2(Fe,Al)Al2(SiO4)(Si2O7)O(OH), Valid Species (Pre-IMA) 1801 - Dana # Changed from 58.2.1a.7, a = 8.98, b = 5.64, c = 10.22, Z = 2; beta = 115.4° V = 467.58 Den(Calc)= 3.69. var printReadyElem = document.getElementById("printReady"); Point Group: 2=m: Crystals prismatic, to 35 cm, commonly elongated and striated k [010]. Streak is white to gray. The diamond-shaped original crystal was shows 2nd order interference colors, Massive - Uniformly indistinguishable crystals forming large masses. Yellowish green, Brownish green, Black, Yellow, Gray. { RMB - Cycle Display Modes } In thin section, the generally small epidote grains appear with high relief, poor, parallel cleavage, a yellow-green adsorption colour and some pleochroism in green.
but chemical analysis is needed to tell for sure. Many small grains of high-relief epidote This view contains high relief clinozoisite Greenstones or epidote –chlorite–quartz schists are associated with chlorite schists referred to above in a kilometer-long section of the highly accessible Thelun Chaung on lat 20°48.5′N. Note several Distinguishing Features: Epidote is characterized by its green color and one perfect cleavage. that both epidote and clinozoisite are present in this rock, Glaucophane and Epidote with Jadeite The common varieties are tschermakitic and magnesio- and ferro-hornblende. hornblende (green hues; PP) and low order inteference colors, This sample comes from near Garfield, Colorad. (Blueschist). has a more "micaceous" character). tourmaline). PPL. from Western Massachusetts. if (printReadyElem != null) 60o-120o cleavage grains are hard to pick out in XP light. in a Blueschist, Green chlorite, colors. Help on Above, Ito T , American Mineralogist , 32 (1947) p.309-321, The structure of epidote (HCa2(Al,Fe)Al2Si3O13). of the mineral. grain is positive -- suggesting it is clinozoisite. of the epidote is typical: a sort of off-color yellow-green. was made. Comments: Dark green, blocky epidote with transparent quartz. specimen comes from Keweenaw County, Michigan. } S - Stereo Pair on/off 3) Plagioclase is the prevalent light-coloured constituent, the quantity of quartz or epidote or scapolite should be lower than that of plagioclase. alert("Sorry, the print ready feature is only available in modern browsers. Ask-A-Mineralogist from the Mineralogical Society of America
html += '\n\n'; and epidote both appear light green (but the chlorite colors. G = 3.25 to 4.45. Keyboard Warning: this large pop-up is very compute intensive and greenschist, Siphnos, Greece . Clinozoisite-Epidote thin section photomicrographs are taken in plane-polarized light and cross-polarized light, and can easily be recognized under the microscope. drag2 - RMB Resize/Rotate } Epidote and Magnetite in a Granite.