Zoisit
| Zoisit | |
 (c) Rob Lavinsky, iRocks.com – CC-BY-SA-3.0 Gul zoisitkristall (1,7 × 1 × 0,8 cm) | |
| Kategori | Sorosilikat - epidot-gruppen |
|---|---|
| Dana klassificering | 58.2.1b.1 |
| Strunz klassificering | 9.BG.10 |
| Kemisk formel | Ca2Al3[O(OH)(SiO4)Si2O7] |
| Färg | Vit, grå, blå, röd, violett, grön, brun, rosa, gul |
| Förekomstsätt | Prismatiska kristaller med ränder, massiv till kolumnformig |
| Kristallstruktur | Ortorombiska |
| Spaltning | Perfet {010}, ofullständig {100} |
| Brott | Ojämnt till konchoidalt |
| Hårdhet (Mohs) | 6,5 - 7 |
| Glans | Glasaktig, pärlaktig på spaltytor |
| Refraktion | nα = 1,696 - 1,700 nβ = 1,696 – 1,702 nγ = 1,702 – 1,718 |
| Ljusbrytning | Biaxial (+) |
| Dubbelbrytning | δ = 0,006 - 0,018 |
| Pleokroism | X = ljusrosa till rödviolett; Y = nästan färglös till ljusrosa eller djupblå; Z = ljusgul till gulgrön |
| Transparens | Transparent till genomskinlig |
| Fluorescens | SWUV: inert till starkt rött till orangerött LWUV: inert eller röd till orangeröd |
| Specifik vikt | 3,10 - 3,36 |
| Referenser | [1][2][3] |
Zoisit, först känd som sualpit, efter dess typlokalitet, är ett mineral, som påminner om epidot och som är ett silikat av kalcium och aluminium med den kemiska formeln Ca2Al3(SiO4)(Si2O7)O(OH).
Mineralet beskrevs av Abraham Gottlob Werner 1805. Han döpte det efter den karniolanska naturforskaren Sigmund Zois von Edelstein, som skickade honom ett prov från Saualpe i Kärnten.[4] Zois insåg att detta var ett okänt mineral när det lämnades till honom av en mineralhandlare, som antas vara Simon Prešern, 1797.[5]
Inte förrän 1954 fann man stenar i ädelstenskvalitet av zoisit. I Tanzania hittade man en blå sten och varieteten kom senare att kallas tanzanit. Det finns även en röd varietet – thulit.
Egenskaper
Zoisit kan vara blå till violett, grön, brun, rosa, gul, grå eller färglös. Blå kristaller är kända under namnet tanzanit. Den har en glasaktig lyster och ett konkoidalt till ojämnt brott. När de är euedriska är zoisitkristaller strimmiga parallellt med huvudaxeln (c-axeln). Parallellt med huvudaxeln är också en riktning av perfekt klyvning. Mineralet är mellan 6 och 7 på Mohs hårdhetsskala, och dess specifika vikt varierar från 3,10 till 3,38, beroende på sorten. Den har vit streckfärg och sägs vara spröd. Klinozoisit är en vanligare monoklin polymorf av Ca2Al3(SiO4)(Si2O7)O(OH).
Förekomst
Zoisit förekommer som prismatiska, ortorombiska (2/m 2/m 2/m) kristaller eller i massiv form, som finns i metamorf och pegmatitisk bergart. Fyndighdeter är kända från Tanzania (tanzanit), Kenya (anyolit), Norge (thulit), Schweiz, Österrike, Indien, Pakistan och staten Washington i USA.
Användning
Transparent material formas till ädelstenar medan genomskinligt till ogenomskinligt material vanligtvis snidas.
Populärkultur
I mangan och animen Sailor Moon är skurken Zoisite uppkallade efter Zoisit.
Bildgalleri
(c) Rob Lavinsky, iRocks.com – CC-BY-SA-3.0
(c) Rob Lavinsky, iRocks.com – CC-BY-SA-3.0
(c) Rob Lavinsky, iRocks.com – CC-BY-SA-3.0
(c) Rob Lavinsky, iRocks.com – CC-BY-SA-3.0
(c) Rob Lavinsky, iRocks.com – CC-BY-SA-3.0
Se även
Referenser
- Den här artikeln är helt eller delvis baserad på material från engelskspråkiga Wikipedia, Tugtupite, 19 januari 2024..
Noter
- ^ http://rruff.geo.arizona.edu/doclib/hom/zoisite.pdf Handbook of Mineralogy
- ^ http://www.mindat.org/min-4430.html Mindat
- ^ http://webmineral.com/data/Zoisite.shtml Webmineral data
- ^ Flint-Rogers, Austin (1937). Introduction to the Study of Minerals. McGraw-Hill Book Company. sid. 478. https://books.google.com/books?id=J8wJAQAAIAAJ
- ^ Faninger, Ernest (1988–1989). ”Neue Daten über die Entdeckung des Zoisits” (på german, slovenian). Geologija: Razprave in poročila (Državna založba Slovenije [State Publishing House of Slovenia]) 31, 32: sid. 609–615. ISSN 0016-7789. http://www.geologija-revija.si/dokument.aspx?id=912.
Vidare läsning
- Hurlbut, Cornelius S.; Klein, Cornelis, 1985, Manual of Mineralogy, 20th ed., ISBN 0-471-80580-7
- Faye, G. H.; Nickel, E. H. (1971). ”On the pleochroism of vanadium-bearing zoisite from Tanzania”. The Canadian Mineralogist 10: sid. 812–821. http://rruff.info/rruff_1.0/uploads/CM10_812.pdf.
Externa länkar
Wikimedia Commons har media som rör Zoisit.- Chisholm, Hugh, ed. (1911). "Zoisite" . Encyclopædia Britannica. Vol. 28 (11th ed.). Cambridge University Press. pp. 1000–1001.
Media som används på denna webbplats
Zoisite-0224-05b.jpg
(c) Rob Lavinsky, iRocks.com – CC-BY-SA-3.0
Zoisite
(c) Rob Lavinsky, iRocks.com – CC-BY-SA-3.0
Zoisite
- Locality: Merelani Hills (Mererani), Lelatema Mts, Arusha Region, Tanzania (Locality at mindat.org)
- Size: miniature, 3.9 x 2.6 x 1.6 cm
- Tanzanite
- This specimen is as jewel-like as you can get for an uncut tanzanite, with absolutely superb glassy lustre that looks polished, combined with a complex sharp termination and a rich natural color. This kind of clarity and perfection of form, combined with the excellent lustre and the color scheme here, has come out only in small amounts of crystals, generally of about this size or smaller, from Block D in recent years. Admittedly, the material of this particular style is not the most intense blue, or purple, or red (on c-axis); but rather has more subtle pink/maroon coloring on the long axis and a lighter pastel hue of blue. It has not been heat-treated, which emphasizes and conforms the blue and purple hues to a standard, while squelching the natural red or pink color on the c-axis. It is pristine and complete-all-around. This is, due to the lighter color palette, not the traditional "major" tanzanite of intense blue (and there, heat treated pieces are acceptable to me when disclosed as such), but rather a more rare and subtle crystal that to me is all the more desirable for its unique qualities. Weighs 32 grams.
Zoisite-33616.jpg
(c) Rob Lavinsky, iRocks.com – CC-BY-SA-3.0
Zoisite
(c) Rob Lavinsky, iRocks.com – CC-BY-SA-3.0
Zoisite
- Locality: Merelani Hills (Mererani), Lelatema Mts, Arusha Region, Tanzania (Locality at mindat.org)
- A stunning, gemmy, "yellow tanzanite" crystal. It is not know why these specimens trickling out now lack the blue color component usually found in tanzanite, but they sure are pretty nonetheless. 13.58 carats 1.7 x 1 x 0.8 cm
Zoisite-271344.jpg
(c) Rob Lavinsky, iRocks.com – CC-BY-SA-3.0
Zoisite (Var.: Tanzanite)
(c) Rob Lavinsky, iRocks.com – CC-BY-SA-3.0
Zoisite (Var.: Tanzanite)
- Locality: Merelani Hills (Mererani), Lelatema Mts, Arusha Region, Tanzania (Locality at mindat.org)
- Size: 7.2 x 3.2 x 2.3 cm.
- This is an unusually fine specimen in several regards. Firstly, it has superb color - probably the prime attribute you first look for in a world-class tanzanite. All three colors of a natural trichroic tanzanite crystal are represented in strength: violet purple, blue, and a rich magenta-red along the c-axis. In the best tanzanites, to my opinion, some of the red from the c-axis (long axis) transmission of light bleeds over and is seen in horizontal planes, from one side or another, as in this case. Many larger tanzanites are too big or too opaque for the red color to transmit through the whole specimen when the piece is lit by a light aligned from the top or bottom: not so with this piece, where the deep red color not only shines out the top when lit from below, but does spill over a bit and mix with the purple hue form the sides. Secondly, it has top glassy lustre and internal brightness both (many larger tanzanites lack one or another feature). Lastly, this piece has excellent geometry. The mine produces singles in abundance, and few clusters, with a different look to them. This piece is a rare, natural doublet cluster, with great symmetry. The twin peaks of the piece are both very gemmy. Cushioned between them, in the crevasse, is a small prehnite ball for accent. This specimen is illustrated with a small and elite group of well-known, important specimens from the mine in the central photo folio of the recent special journal/book dedicated to Merelani's riches, MINERALOGICAL RECORD, Nov-Dec 2009. Weighs 113 grams.
Zoisite-221337.jpg
(c) Rob Lavinsky, iRocks.com – CC-BY-SA-3.0
Zoisite (Var.: Tanzanite)
(c) Rob Lavinsky, iRocks.com – CC-BY-SA-3.0
Zoisite (Var.: Tanzanite)
- Locality: Merelani Hills (Mererani), Lelatema Mts, Arusha Region, Tanzania (Locality at mindat.org)
- Size: 2.3 x 0.8 x 0.7 cm.
- This is a gorgeous crystal with all 3 colors of the natural trichroic crystal present and strongly showing down different axes of view; riveting glassy luster; incredible clarity and transparency; and a full-sized thumbnail at 16.57 carats. Ex. Marilyn Dodge Collection.
Zoisite-274990.jpg
(c) Rob Lavinsky, iRocks.com – CC-BY-SA-3.0
Zoisite (Var.: Tanzanite)
(c) Rob Lavinsky, iRocks.com – CC-BY-SA-3.0
Zoisite (Var.: Tanzanite)
- Locality: Merelani Hills (Mererani), Lelatema Mts, Arusha Region, Tanzania (Locality at mindat.org)
- Size: 2.4 x 1.7 x 0.8 cm.
- Rare, bi-colored tanzanites were prominently featured in the recent Merelani Hills article in the Mineralogical Record. This striking gem crystal has an interesting, double termination above the pastel yellow-green, base. The upper portion of the crystal displays the classic, 3-way pleochroism found in many zoisites: the A-axis faces are a pleasing purple; the B-axis faces are light blue; and the vertical C-axis show shades of red, even with the yellow-green base. This is a much in demand, highly representative rarity.
Zoisite-249265.jpg
(c) Rob Lavinsky, iRocks.com – CC-BY-SA-3.0
Zoisite (Var.: Tanzanite)
(c) Rob Lavinsky, iRocks.com – CC-BY-SA-3.0
Zoisite (Var.: Tanzanite)
- Locality: Merelani Hills (Mererani), Lelatema Mts, Arusha Region, Tanzania (Locality at mindat.org)
- Size: 1.8 x 1.1 x 0.8 cm.
- A very rare, gemmy and lustrous, yellow tanzanite crystal thumbnail from the Merelani Hills of Tanzania. The internal crazing really adds to the attractiveness of this crystal, next to the gemmy areas. Yellow tanzanite is seldom encountered and is very seldom on the market. This rarity is complete-all-around and pristine. Weighs 16.38 carats.