Apophyllite group

from Wikipedia, the free encyclopedia
Apophyllite group
Apophyllite- (KF) -119082.jpg
Fluorapophyllite- (K) from Jalgaon District , Maharashtra , India (size: 8.8 cm × 5.2 × 4.4 cm)
General and classification
other names
  • Ichthyophthalmit (fish-eye stone)
  • Tesselite
  • Brünnichite
  • Oxahverite (Oxhaverite)
  • Albin
  • Xylochlor
chemical formula (K, Na) Ca 4 Si 8 O 20 (F, OH) · 8H 2 O, see individual minerals
Mineral class
(and possibly department) 		Silicates and germanates (phyllosilicates)
System no. to Strunz
and to Dana 		9.EA.15 ( 8th edition : VIII / H.01)
72.03.01
Crystallographic Data
Crystal system tetragonal or orthorhombic
Crystal class ; symbol ditetragonal-dipyramidal; 4 / m  2 / m  2 / m or orthorhombic-dipyramidal; 2 / m  2 / m  2 / m
Space group see single minerals
Frequent crystal faces {110}, {101}, {001}, {210}
Twinning Twin construction around c [001], multiple twins possible
Physical Properties
Mohs hardness 4.5 to 5
Density (g / cm 3 ) 2.33 to 2.37 (measured); 2.30 to 2.37 (calculated)
Cleavage very perfect after {001}
Break ; Tenacity uneven; brittle
colour colorless, white, gray, rose to flesh red, yellowish, greenish, bluish
Line color white to light gray
transparency translucent to translucent
shine Glass luster, mother-of-pearl luster on {001} and on cleavage surfaces
Other properties
Chemical behavior Easily decomposed by acids such as HCl and HNO 3 to form a slimy residue
Special features Flakes open when heated

The apophyllite group ( apophyllite for short ) is a name for a group of relatively common minerals from the mineral class of silicates . Structurally, the apophyllites belong to the layered silicates (phyllosilicates). They crystallize in the tetragonal crystal system or in the orthorhombic crystal system with the chemical composition (K, Na) Ca 4 Si 8 O 20 (F, OH) · 8H 2 O. The elements potassium and sodium or fluorine and hydroxide ions in the round brackets can represent each other in the formula ( substitution , diadochie), but are always in the same proportion to the other components of the mineral. The minerals of the apophyllite group are found, often accompanied by zeolites, as secondary formations in cavities in basalts, phonolites or other basic volcanics.

Etymology and history

Idiomorphic, transparent fluorapophyllite (K) crystal on quartz from the Jalgaon district , Maharashtra, India (size: 11.3 cm × 10.1 cm × 4 cm)

Apophyllite was first mentioned in Sweden in 1784 by Carl Rinman, the son of Sven Rinman , as "Zeolite from Hellesta" and was given the trivial names "Gässten" and "Brausestein". As an independent mineral, apophyllite was first described by José Bonifácio de Andrada e Silva as "Ichthyophthalme", ​​the original occurrence of "Ichthyophthalm" being the island of Utö in the southern Stockholm archipelago . Abraham Gottlob Werner incorporated the name into "Fischaugenstein". The name refers to the pearlescent sheen of the base surface, which resembles a cooked fish eye. In 1801, René-Just Haüy originally considered an apophyllite from Iceland to be a variety of the mesotype established by him and named it "Mésotype époinlée", but four years later referred to the mineral with regard to its behavior in front of the solder pipe (after the Greek word ἀπόφύλλίζω [apophyllizo ] for "defoliate") as apophyllite. David Brewster has found that the apophyllite from the Faroe Islands shows the characteristics of biaxial crystals in polarized light and established its own species "tesselite" (from the Latin word "tessella", diminutive of tessera, cube). Pete Dunn and Wendell Wilson provide an overview of other historical names. Apophyllite crystals are also associated worldwide with the occurrences in the Indian Dekkan - Trapp . Since the construction of the railroad between Mumbai and Pune in 1851, but no later than the beginning of the construction boom in the early 1970s, innumerable excellent apophyllite specimens have literally been recovered from the triangle formed by the cities of Mumbai, Pune and Nashik .

While the name "apophyllite" does not stand for a single mineral, but for two rows of mixed crystals and thus for an entire mineral group, the names of the end links were renamed by the IMA in 1978 . After various other renaming, the apophyllite group now consists of the following minerals recognized by the IMA, whereby a further mineral, namely carletonite, is occasionally added to the apophyllite group.

  • Fluorapophyllite- (K) (formerly fluorapophyllite and apophyllite- (KF) ); ditetragonal-dipyramidal; KCa 4 [(F, OH) | (Si 4 O 10 ) 2 ] • 8H 2 O
  • Hydroxyapophyllite (K) (formerly hydroxyapophyllite and apophyllite (KOH) ); ditetragonal-dipyramidal; KCa 4 [(OH, F) | (Si 4 O 10 ) 2 ] • 8H 2 O
  • Fluorapophyllite- (Na) (formerly Natro-Apophyllite and Apophyllite- (NaF) ); orthorhombic-dipyramidal; NaCa 4 [F | (Si 4 O 10 ) 2 ] • 8H 2 O
  • Fluoroapophyllite (Cs) (IMA 2018-108a); ditetragonal-dipyramidal; CsCa 4 (Si 8 O 20 ) F (H 2 O) 8 or CsCa 4 [F | (Si 4 O 10 ) 2 ] · 8H 2 O
  • Carletonite ; ditetragonal-dipyramidal; KNa 4 Ca 4 [(OH, F) | (CO 3 ) 4 | Si 8 O 18 ] · H 2 O

classification

In the now outdated, but still in use 8th edition of the mineral classification according to Strunz , the apophyllites belonged to the mineral class of "silicates and germanates" and there to the department of "phyllosilicates", where the three end links are the apophyllite group with system no. VIII / H.01 .

The 9th edition of Strunz's mineral systematics , which has been in effect since 2001 and is used by the International Mineralogical Association (IMA), also assigns apophyllites to the class of “silicates and germanates” and there to the “phyllosilicates” section. However, this section is further subdivided according to the structure of the layers, so that the three apophyllite end links according to their structure can be found in the subsection “Simple tetrahedral networks with 4, 5, (6) and 8 participating rings”, where they in turn form the apophyllite group with the system no. Form 9.EA.15 .

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the apophyllites to the class of "silicates and Germanates" and there in the department of "layered silicate minerals". Here the three apophyllite end links together with carletonite also form the "apophyllite group" with the system no. 72.03.01 within the subdivision of " Layered silicates: two-dimensional unlimited layers with rings other than six-membered: 3-, 4-, or 5-membered rings and 8-membered rings ".

Chemism

The three group end members form mixed crystal rows. These cannot be distinguished from one another without extensive analysis and usually do not have the ideal composition. The F / (OH) ratio changes with the end links fluorapophyllite (K) and hydroxyapophyllite (K). All three end links have high calcium contents between 24 and 25% by weight, potassium is present in the formulas of fluorapophyllite (K) and hydroxyapophyllite (K), while sodium is only present in fluorapophyllite (Na). In some ammonium-containing apophyllites, up to 25% of the stoichiometric K + has been replaced by NH 4 + . It is possible that there is a further series of mixed crystals between fluorapophyllite- (K) and a hypothetical end member fluorapophyllite- (NH 4 ). In particular, Indian apophyllites from highly porous basalts, which have maximum contents of 600 ppm to 750 ppm vanadium, have contents of 1600 ppm vanadium and 350 ppm manganese in their trace elements . It turned out that the vanadium as tetravalent vanadium in the form of the vanadyl ion (VO 2+ ) is responsible for the green color of the Indian apophyllites and also for their dichroism.

Crystal structure

[SiO 4 ] tetrahedron layer of apophyllite, projected onto plane (001). The SiO 4 tetrahedra form rings of four, the tips of which point alternately up and down.
Apophyllite structure: __ Ca 2+ , __ ( Na , K ) + , __ O 2− , __ F - , __ H + , __ Si 4+

The minerals of the apophyllite group crystallize tetragonally in the space group P 4 / mnc (space group no.128 ) (fluorapophyllite (K) and hydroxyapophyllite (K)) or orthorhombically in the space group Pnnm (space group no.58 ) (fluorapophyllite- (N / A)). Template: room group / 128 Template: room group / 58

Apophyllite has an unusual single-layer structure, which consists of endless layers or networks of SiO 4 tetrahedra parallel (001) (see also the figures on the right). In contrast to the six-membered rings of the mica group, these layers are built up from four-membered and eight-membered rings of corner-sharing [SiO 4 ] 4− tetrahedra. The rings of four alternately point up and down with respect to the c-axis. The layers are linked to one another by large calcium ions, which connect two oxygen atoms, one (OH, F) ion and two H 2 O molecules from each of the neighboring layers . The connection of the H 2 O molecules with the oxygen atoms of the SiO 4 tetrahedra takes place via hydrogen bonds. Each (OH, F) ion is surrounded by four coplanar calcium ions, while each potassium or sodium ion is surrounded by eight H 2 O molecules. In this way, the tetrahedron layers change continuously with layers consisting of the large cations of calcium, sodium and potassium as well as F - / OH - and H 2 O molecules. The arrangement of the layers parallel (001) explains the very perfect cleavage of the apophyllites in this direction.

The crystal water is expelled in two steps between 330 ° C and 440 ° C. If fluorine dominates over hydroxide, this release of water takes place at temperatures which are around 20 ° C higher than in the opposite case.

properties

morphology

The minerals of the apophyllite group are found in almost always grown crystals, up to 20 cm in size and up to 1 kg in weight, which essentially occur in three different basic types with the main surface shapes {100}, {101}, {001} and {210} ( see also the adjacent crystal drawings). When comparing with historical crystal drawings, it must be noted that the arrangement of the crystals in modern drawings is rotated by 45 ° compared to the previous morphological orientation.

  • dipyramidal apophyllite crystal

  • prismatic apophyllite crystal

  • isometric apophyllite crystal

  • tabular apophyllite crystals. the same colors mean the same surface shapes

Type I crystals are pyramidal with the tetragonal dipyramid {101} which determines the costume and which can be modified by the prism {110} and the basic pinacoid {001}. Type II crystals are prismatic to cube-like due to the predominance of {110} and {001}, which are often in equilibrium, and type III crystals are tabular due to the dominance of {001}. Due to the simultaneous occurrence of {110} and {210}, the surfaces of {110} often show clear and deep stripes parallel to the edges and rounding. In contrast to this is the opinion, which was already held at the end of the 19th century, that the striation of the Apophyllite is caused by structural errors with the formation of countless adjacent sub-individuals, with the individual blocks being offset by 1 ° to 3 °. The surfaces of {001} are often matt or even rough. The angle between surfaces (111) and (001) is 119.5 °, between two (111) surfaces 104 ° and between (111) and (100) 128 °. In addition to crystals, apophyllite also forms leaf-like, shell-like, granular or radiant as well as chalcedony-like or porcelain-like aggregates.

physical and chemical properties

In its pure form, apophyllite is colorless and water-clear and transparent. Due to multiple refraction due to lattice construction defects or polycrystalline formation, the crystals are much more often white or show due to foreign atoms (e.g. tetravalent vanadium in the form of the vanadyl ion VO 2+ ) or due to inclusions of other minerals ( celadonite , chlorite , hematite , Goethite ) gray, rose to flesh red, yellowish, greenish to green or even bluish color tones, whereby the transparency decreases accordingly. Mozartite , which was made responsible for yellow, red and beige tones, does not appear as an inclusion mineral. Occasionally even dichroic crystals with blue-green colors parallel [001] and pale yellow-green colors perpendicular thereto were encountered. It has been shown that high levels of vanadium are responsible for both the dichroism and the green color of at least the Indian apophyllites.

The stroke color of the Apophyllite, however, is always white or light gray. The surfaces of the translucent to transparent crystals have a glass-like sheen on the surfaces of {110} , whereas on the surfaces of {001} and cleavage surfaces they have a pearlescent sheen . Apophyllite have a very perfect cleavage according to {001}, occasionally an imperfect cleavage according to {110} is mentioned. Due to its brittleness, apophyllite breaks in a similar way to amblygonite , with the fracture surfaces being uneven. With a Mohs hardness of 4 to 5, apophyllites are among the medium-hard minerals that, like the reference minerals fluorite and apatite, can be scratched more or less easily with a pocket knife. The measured densities for Apophyllite are 2.33 g / cm³ to 2.37 g / cm³, the calculated densities are between 2.30 g / cm³ and 2.37 g / cm³.

In the thin section, apophyllites are colorless and show anomalous interference colors. Apophyllite is characterized by a remarkably low birefringence and a variation in the optical character from positive to negative, which can often be observed in the same crystal. Apophyllites are often optically anomalous and biaxial. The optical anomalies of apophyllite have long been known; In addition to the biaxial nature, they express themselves in the division of fields and the “apophyllite rings”, a special color in the interference figures. Apophyllite is strongly pyroelectric in such a way that when the heated crystal cools, the ends of its main axis are charged positively and the central regions are negatively charged.

By splitting off the crystal water, apophyllites show a clear reaction before the soldering tube . In doing so, they peel open in a characteristic way and easily melt into white, blistered enamel, but on charcoal into a clear, transparent ball. The flame only turns violet in the vicinity of the sample. Becomes dull in the flask while releasing water; Fluorine reaction. Easily decomposed by hydrochloric acid and nitric acid , difficult to decompose by sulfuric acid , forming a slimy to gelatinous residue that is more difficult to attack after glowing. The powder has a strong alkaline reaction, even after glowing.

Modifications and varieties

Many apophyllites are zoned continuously or discontinuously. Apophyllites from the Sampo Mine in Japan show z. B. potassium-rich marginal zones (fluorapophyllite- (K)) and sodium-rich core zones (fluorapophyllite- (Na)). Apophyllites from various sites that were more or less converted into calcite were referred to as “albine” . A variety from Iceland that was colored olive-green by traces of iron was named "xylochlor" (after the Greek words ξύλον [xylos] for "wood" and χλωρός [chloros] for "green"). The color is probably not caused by iron, but by vanadium (see above).

Education and Locations

Green fluorapophyllite (K) crystals in grinding quality from the Pashan Hills near Pune in the district of the same name, Maharashtra, India (size: 3.9 cm × 3.4 cm × 2.5 cm)
Transparent fluorapophyllite (K) crystal next to dark heulandite from the Jalgaon district , Maharashtra, India (size: 8 cm × 4.5 cm × 3 cm)

Minerals of the apophyllite group are found as secondary formations in cavities and former gas bubbles in basalt , phonolite or other volcanic rocks . Accompanying minerals are almost always zeolites such as stilbit , laumontite and scolezite, as well as prehnite , datolite and pectolite . Such stages often come from the Indian province of Poona . In amphibolites and skarns , apophyllites are also accompanied by prehnite, datolite and pectolite. A second focus of education are alpinotype rifts such as B. in the Alps, where the apophyllites also from zeolites, but z. B. also be accompanied by fluoroapatite . Finally, the representatives of the apophyllite group are found on hydrothermal corridors, where they in turn with certain zeolites such as. B. Harmotome and Analcim , but also with calcite , are associated. A typical site for this paragenesis is St. Andreasberg in the Harz Mountains . Finally, one also knows formations through thermal springs such as B. in the masonry of the baths of Plombières-les-Bains, Vosges , Lorraine , France , where pyramidal apophyllite crystals sit on grape hyalite .

So far (as of 2016) around 1100 sites for "Apophyllite" are known worldwide. Fluorapophyllite- (K) was found in about 320 of these locations, hydroxyapophyllite- (K) in about 85 locations and fluorapophyllite- (Na) in about 10 locations. For the rest of the sites, only - since no analyzes exist - “apophyllite” can be specified without differentiation.

The hydroxyapophyllite (K) type locality is the Ore Knob Mine, Ore Knob, Ashe County , North Carolina , USA . ( Coordinates of the Ore Knob Mine ). The type locality of the fluorapophyllite (Na) is the Sampo mine in Japan . For fluorapophyllite- (K) no type locality is shown, but the first place where this mineral was found is the Sörgrube near Hällestad not far from Finspång in the Landskap Östergötland , which corresponds to today's Swedish province of Östergötland County . Hällestad is identical to the oldest reported apophyllite occurrence by Carl Rinman.

use

Cut apophyllite, 0.60 ct, from India

Minerals of the apophyllite group, due to their size, color and luster and paragenesis with zeolite minerals, are primarily interesting formations for collectors. Due to its potassium content, fluorapophyllite (K) is an important mineral for 40 Ar / 39 Ar and Rb-Sr- Geochronology . Since minerals of the apophyllite group are difficult to treat due to their very perfect cleavage, they are hardly abraded. The best material for faceting are colorless crystals from India, from which stones up to 15 ct are cut. In the Smithsonian Institution in Washington, DC there is a colorless apophyllite with steep facets and a weight of 15.4 ct. Apophyllites with a pearlescent luster are made into cabochons.

See also

literature

  • Paul Ramdohr , Hugo Strunz : Klockmann's textbook of mineralogy . 16th edition. Enke , Stuttgart 1978, ISBN 3-432-82986-8 , pp. 739-740 (first edition: 1891).
  • Martin Okrusch , Siegfried Matthes : Mineralogy: An introduction to special mineralogy, petrology and deposit science . 8th edition. Springer, Berlin Heidelberg 2009, ISBN 978-3-540-78200-1 , p. 739-740 (first edition: 1983).
  • Helmut Schrätze, Karl-Ludwig Weiner: Mineralogy. A textbook on a systematic basis . de Gruyter, Berlin; New York 1981, ISBN 3-11-006823-0 , pp. 654 .
  • Fluorapophyllite [Fluorapophyllite- (K)], In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America , 2001 ( PDF, 76 kB )
  • Hydroxyapophyllite [Hydroxyapophyllite- (K)], In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America , 2001 ( PDF, 70 kB )
  • Natroapophyllite [Fluorapophyllite- (Na)], In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (eds.): Handbook of Mineralogy, Mineralogical Society of America , 2001 ( PDF, 76 kB )

Web links

Commons : Apophyllite  - collection of images, videos and audio files

Individual evidence

  1. ↑ a b c d William Alexander Deer , Robert Andrew Howie , Jack Zussman : An introduction to the rock-forming minerals . 2nd Edition. Longman Scientific & Technical , Harlow (Essex) 1992, ISBN 0-582-30094-0 , pp.  382-383 .
  2. ↑ a b c d e Paul Ramdohr , Hugo Strunz : Klockmann's textbook of mineralogy . 16th edition. Enke , Stuttgart 1978, ISBN 3-432-82986-8 , pp.  739-740 (first edition: 1891).
  3. ↑ José Bonifácio de Andrada e Silva : Brief statement of the properties and characteristics of some new fossils from Sweden and Norway together with some chemical remarks about them . In: General Journal of Chemistry . 4 (issue 19). Verlag S. Hirzel , Berlin 1800, p.  32 ( available online in the General Journal of Chemistry p. 32 in the Google book search).
  4. ↑ a b c d e f g h Carl Hintze : Handbuch der Mineralogie. Second volume. Silicates and titanates . 1st edition. Verlag Veit & Co., Leipzig 1897, pp. 1731-1745.
  5. ↑ a b c Pete J. Dunn, Wendell E. Wilson (1978): Nomenclature revisions in the Apophyllite group: Hydroxyapophyllite, Apophyllite, Fluorapophyllite. In: The Mineralogical Record , Volume 9, pp. 95-98 ( PDF, 2.85 MB ).
  6. ^ IMA / CNMNC List of Mineral Names; May 2016 (PDF 1.6 MB)
  7. ↑ Malcom E. Back: Fleischer's Glossary of Mineral Species . 11th edition. Mineralogical Record, Tucson, Arizona (AZ) 2014, p. 12 .
  8. ↑ a b c d e Hugo Strunz , Ernest H. Nickel : Strunz Mineralogical Tables . 9th edition. E. Schweizerbart'sche Verlagbuchhandlung (Nägele and Obermiller), Stuttgart 2001, ISBN 3-510-65188-X , p.  659 .
  9. ↑ Atali A. Agakhanov, Leonid A. Pautov, Anatoly V. Kasatkin, Vladimir Yu. Karpenko, Elena Sokolova, Maxwell C. Day, Frank C. Hawthorne, Vyacheslav A. Muftakhov, Igor V. Pekov, Fernando Cámara, Sergey N. Britvin: Fluorapophyllite- (Cs), CsCa 4 (Si 8 O 20 ) F (H 2 O) 8 , a new apophyllite-group mineral from the Darai-Pioz Massif, Tien-Shan, northern Tajikistan . In: The Canadian Mineralogist . tape 57 , no. 6 , 2019, pp. 965–971 , doi : 10.3749 / canmin.1900038 (English).
  10. ↑ a b c d Fluorapophyllite , In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America , 2001 ( PDF, 76 kB )
  11. ↑ a b Hydroxyapophyllite , In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America , 2001 ( PDF, 70 kB )
  12. ↑ a b Natroapophyllite , In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America , 2001 ( PDF, 76 kB )
  13. ^ A b c Giselle F. Marriner, John Tarney, J. Ian Langford (1990): Apophyllite group: effects of chemical substitutions on dehydration behavior, recrystallization products and cell parameters. In: Mineralogical Magazine , Volume 54, pp. 567-577 ( PDF, 1.29 MB ).
  14. ^ A b c George R. Rossman (1974): Optical Spectroscopy of Green Vanadium Apophyllite from Poona, India. In: American Mineralogis , Volume 59, pp. 621-622 ( PDF, 223 kB ).
  15. ^ A b George R. Rossman: Optical Spectroscopy . In: Grant S. Henderson, Daniel R. Neuville, Robert T. Downs (Eds.): Spectroscopic Methods in Mineralogy and Material Sciences . 1st edition. Reviews in Mineralogy and Geochemistry, No. 78 . De Gruyter, Boston, ISBN 978-0-939950-93-5 , pp. 371-398 .
  16. ↑ Martin Okrusch , Siegfried Matthes : Mineralogie: An introduction to special mineralogy, petrology and deposit science . 8th edition. Springer, Berlin Heidelberg 2009, ISBN 978-3-540-78200-1 , p.  739-740 (first edition: 1983).
  17. ↑ George Y. Chao (1971): The Refinement of the Crystal Structure of Apophyllite - Determination oh the hydrogen positions by x-ray diffraction. In: The American Mineralogist , Volume 56, pp. 1234-1242 ( PDF, 468 kB ).
  18. ^ Berthold Ottens (2000): News from the Indian Dekkan Trapp. In: Mineralien-Welt , Volume 11 (Issue 1), pp. 48-62.
  19. ↑ Johann Rumpf (1879): About the crystal structure of apophyllite. In: Tschermaks Mineralogische und Petrographische Mitteilungen NF , Volume 2, pp. 369–391.
  20. ^ A b Berthold Ottens : India: Minerals - Locations - Deposits . 1st edition. Christian Weise Verlag, Munich 2011, ISBN 978-3-921656-76-1 , p.  277-283 .
  21. ↑ Pete J. Dunn, Roland C. Rouse, Julie A. Norberg (1978): Hydroxyapophyllite, a new mineral, and a redefinition of the apophyllite group. I. Description, currences, and nomenclature. In: American Mineralogist , Volume 63, pp. 196-202.
  22. ↑ a b Hiruharo Matsueda, Yasuno Minurua, John Rucklidge (1981): Natroapophyllite, a new orthorhombic sodium analog of apophyllite - Description, occurrence, and nomenclature. In: American Mineralogist , Volume 66, pp. 410-423 ( PDF, 1.36 MB ).
  23. ^ David Brewster : On a New Optical and Mineralogical structure, exhibited in certain specimens of Apophyllite an other minerals . In: The Edinburgh Philosophical Journal . tape  1 . Publisher Archibald Constable and Company , Edinburgh 1819, p 1–8 ( available online in The Edinburgh Philosophical Journal p. 1 ff. In the Google book search).
  24. ^ Wilhelm Gottlieb Hankel : About the thermoelectric properties of Kalkspathes, Berylles, Idocrases (Vesuvianes) and Apophyllites . In: Reports on the negotiations of the Royal Saxon Society of Sciences in Leipzig. Mathematical-physical class . tape  26 . Verlag S. Hirzel , Leipzig 1875, p. 465–472 ( available online in Reports on the Negotiations of the Royal Saxon Society of Sciences in Leipzig, pp. 465 ff. In the Google book search).
  25. ^ Carl Rinman : Experiment with zeolite or guests (shower stone) . In: The Royal Swedish Academy of Sciences New Essays on Nature, Housekeeping, and Mechanics for 1784 . tape  5 . Verlag Johann Samuel Heinsius, Leipzig 1786, p. 51–68 ( available online in The Royal Swedish Academy of Sciences New Treatises from the Study of Nature, Household Art and Mechanics, pp. 51 ff. In Google Book Search).
  26. ↑ Mindat - Number of localities for the apophyllite group
  27. ↑ Mindat - Number of localities for fluorapophyllite (K)
  28. ↑ Find location list for fluorapophyllite (K) in the Mineralienatlas and in Mindat
  29. ↑ Mindat - number of localities for hydroxyapophyllite (K)
  30. ↑ Find location list for Hydroxyapophyllite- (K) in the Mineralienatlas and in Mindat
  31. ↑ Mindat - Number of localities for fluorapophyllite (Na)
  32. ↑ Find location list for fluorapophyllite (Na) in the Mineralienatlas and in Mindat
  33. ↑ Mindat - type locality for hydroxyapophyllite (K)
  34. ↑ Mindat - type locality for fluorapophyllite (Na)
  35. ↑ Mindat - First place of discovery of fluorapophyllite (K)
  36. ↑ Thomas H. Fleming, Kenneth A. Foland, David A. Elliot (1990): Apophyllite 40 Ar / 39 Ar and Rb-Sr geochronology: Potential utility and application to the timing of secondary mineralization of the Kirkpatrick Basalt, Antarctica. In: Journal of Geophysical Research , Volume 104, pp. 20,081-20,095.
  37. ↑ Vladimir Bukanov. Colorful stones - Russian Gemstones Encyclopedia