The name apophyllite refers to a specific group of phyllosilicate minerals, a class of minerals that also includes the micas. Originally, the group name referred to a specific mineral, but was redefined in 1978 to stand for a class of minerals of similar chemical makeup that comprise a solid solution series, and includes the members fluorapophyllite, hydroxyapophyllite, and natroapophyllite. The name apophyllite is derived from the Greek apophylliso, meaning "it flakes off," a reference to this class's tendency flake apart when heated, due to water loss. These minerals are typically found as secondary minerals in basalt. Image File history File links Metadata No higher resolution available. ... A mineral is a naturally occurring substance formed through geological processes that has a characteristic chemical composition, a highly ordered atomic structure and specific physical properties. ... This article or section does not cite any references or sources. ... General Name, Symbol, Number potassium, K, 19 Chemical series alkali metals Group, Period, Block 1, 4, s Appearance silvery white Standard atomic weight 39. ... For sodium in the diet, see Edible salt. ... General Name, Symbol, Number calcium, Ca, 20 Chemical series alkaline earth metals Group, Period, Block 2, 4, s Appearance silvery white Standard atomic weight 40. ... General Name, Symbol, Number silicon, Si, 14 Chemical series metalloids Group, Period, Block 14, 3, p Appearance as coarse powder, dark grey with bluish tinge Standard atomic weight 28. ... General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Standard atomic weight 15. ... General Name, Symbol, Number fluorine, F, 9 Chemical series halogens Group, Period, Block 17, 2, p Appearance Yellowish brown gas Atomic mass 18. ... Hydroxide is a polyatomic ion consisting of oxygen and hydrogen: OH− It has a charge of −1. ... Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ... In mineralogy, shape and size give rise to descriptive terms applied to the typical appearance, or habit of crystals. ... A crystal system is a category of space groups, which characterize symmetry of structures in three dimensions with translational symmetry in three directions, having a discrete class of point groups. ... Cleavage, in mineralogy, is the tendency of crystalline materials to split along definite planes, creating smooth surfaces, of which there are several named types: Basal cleavage: cleavage parallel to the base of a crystal, or to the plane of the lateral axes. ... For fractures in geologic formations, see Rock fracture. ... Mohs scale of mineral hardness characterizes the scratch resistance of various minerals through the ability of a harder material to scratch a softer. ... Lustre (American English: luster) is a description of the way light interacts with the surface of a crystal, rock or mineral. ... The refractive index (or index of refraction) of a medium is a measure for how much the speed of light (or other waves such as sound waves) is reduced inside the medium. ... Pleochroism is an optical phenomenon in which grains of a rock appear to be different colors when observed at different angles,under a petrographic microscope. ... The streak (also called powder color) of a mineral is the color of the powder produced when it is dragged across a unweathered surface. ... Relative density (also known as specific gravity) is a measure of the density of a material. ... A mineral is a naturally occurring substance formed through geological processes that has a characteristic chemical composition, a highly ordered atomic structure and specific physical properties. ... Rock with mica Mica sheet Mica flakes The mica group of sheet silicate minerals includes several closely related materials having highly perfect basal cleavage. ... Fig. ... Basalt Basalt (IPA: ) is a common gray to black extrusive volcanic rock. ...

Though relatively unfamiliar to the general public, apophyllites are fairly prevalent around the world, with specimens coming from some of the worlds most well-known mineral localities. These localities include: Poona, India; the Harz Mountains of Germany, Mont Saint-Hilaire in Canada, and Kongsberg, Norway, with other locations in Scotland, Ireland, Brazil, Japan, and throughout the United States. , Pune (Marathi: पुणे ,pronunciation: ) is a city located in the western Indian state of Maharashtra. ... The Harz is a mountain range in northern Germany. ... Mont Saint-Hilaire (en. ... Kongsberg (lit. ... This article is about the country. ...

Apophyllites are almost exclusively used as collector's minerals, a role in which they are very popular. This popularity is due to a combination of factors, including their abundance, color variety, and well-defined crystals.

Species of Apophyllite

• Fluorapophyllite, (K, Na)Ca₄Si₈O₂₀(F, OH) · 8H₂O - white, colorless, yellow, green, violet
• Hydroxyapophyllite, KCa₄Si₈O₂₀(OH, F) · 8H₂O - white, colorless
• Natroapophyllite, (K, Na)Ca₄Si₈O₂₀F · 8H₂O - brown, yellow, colorless

General Name, Symbol, Number potassium, K, 19 Chemical series alkali metals Group, Period, Block 1, 4, s Appearance silvery white Standard atomic weight 39. ... For sodium in the diet, see Edible salt. ... General Name, Symbol, Number calcium, Ca, 20 Chemical series alkaline earth metals Group, Period, Block 2, 4, s Appearance silvery white Standard atomic weight 40. ... General Name, Symbol, Number silicon, Si, 14 Chemical series metalloids Group, Period, Block 14, 3, p Appearance as coarse powder, dark grey with bluish tinge Standard atomic weight 28. ... General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Standard atomic weight 15. ... General Name, Symbol, Number fluorine, F, 9 Chemical series halogens Group, Period, Block 17, 2, p Appearance Yellowish brown gas Atomic mass 18. ... Hydroxide is a polyatomic ion consisting of oxygen and hydrogen: OH− It has a charge of −1. ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Standard atomic weight 15. ... General Name, Symbol, Number potassium, K, 19 Chemical series alkali metals Group, Period, Block 1, 4, s Appearance silvery white Standard atomic weight 39. ... General Name, Symbol, Number calcium, Ca, 20 Chemical series alkaline earth metals Group, Period, Block 2, 4, s Appearance silvery white Standard atomic weight 40. ... General Name, Symbol, Number silicon, Si, 14 Chemical series metalloids Group, Period, Block 14, 3, p Appearance as coarse powder, dark grey with bluish tinge Standard atomic weight 28. ... General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Standard atomic weight 15. ... Hydroxide is a polyatomic ion consisting of oxygen and hydrogen: OH− It has a charge of −1. ... General Name, Symbol, Number fluorine, F, 9 Chemical series halogens Group, Period, Block 17, 2, p Appearance Yellowish brown gas Atomic mass 18. ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Standard atomic weight 15. ... General Name, Symbol, Number potassium, K, 19 Chemical series alkali metals Group, Period, Block 1, 4, s Appearance silvery white Standard atomic weight 39. ... For sodium in the diet, see Edible salt. ... General Name, Symbol, Number calcium, Ca, 20 Chemical series alkaline earth metals Group, Period, Block 2, 4, s Appearance silvery white Standard atomic weight 40. ... General Name, Symbol, Number silicon, Si, 14 Chemical series metalloids Group, Period, Block 14, 3, p Appearance as coarse powder, dark grey with bluish tinge Standard atomic weight 28. ... General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Standard atomic weight 15. ... General Name, Symbol, Number fluorine, F, 9 Chemical series halogens Group, Period, Block 17, 2, p Appearance Yellowish brown gas Atomic mass 18. ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Standard atomic weight 15. ...

References

• WebMineral Listing
• MinDat Listing
• Mineral Galleries
• Colville AA, Anderson CP, Black PM (1971). "Refinement of the crystal structure of apophyllite: I. X-ray diffraction and physical properties". American Mineralogist 56: 1222-1233.