triphylite

{{Short description|Mineral}}

{{Expand German|Triphylin|date=July 2015}}

{{Infobox mineral

| name =

| category = Phosphate minerals

| boxwidth =

| boxbgcolor =

| image = Triphylite-112567.jpg

| imagesize =

| caption = Triphylite crystal in matrix, collected from Smith Quarry (Chandler Mills Quarry), Newport, New Hampshire {{coord|43|21|28|N|72|15|8|W}}{{cite web|title=Chandlers Mill Quarry, Newport, Sullivan Co., New Hampshire, USA|url=http://www.mindat.org/maps.php?id=3940|publisher=MinDat.org}}

| formula = LiFePO₄

| IMAsymbol = Trp{{Cite journal|last=Warr|first=L.N.|date=2021|title=IMA–CNMNC approved mineral symbols|journal=Mineralogical Magazine|volume=85|issue=3|pages=291–320|doi=10.1180/mgm.2021.43|bibcode=2021MinM...85..291W|s2cid=235729616|doi-access=free}}

| molweight =

| strunz = 8.AB.10

| system = Orthorhombic

| class = Dipyramidal (mmm)
H-M symbol: (2/m 2/m 2/m)

| symmetry = Pmnb

| color = Green–blue gray, brown–black

| habit = Massive, granular, prismatic

| twinning =

| cleavage = {100} perfect, {010} imperfect, {011} poor

| fracture = Uneven–subconchoidal

| mohs = 4–5

| luster = Vitreous–subresinous

| polish =

| refractive = n_α=1.675–1.694, n_β=1.684–1.695, n_γ=1.685–1.700

| opticalprop = Biaxial (+), 2V = 0°–65°

| birefringence = δ = 0.0060–0.0080

| pleochroism =

| fluorescence=

| absorption =

| streak = White–grayish white

| gravity =

| density =

| melt =

| fusibility =

| diagnostic =

| solubility =

| diaphaneity = Transparent–translucent

| unit cell = a = 6.0285(6) Å, b = 10.3586(9) Å, c = 4.7031(3) Å, Z = 4

| other =

| references ={{cite web|url=http://webmineral.com/data/Triphylite.shtml|title=Triphylite|publisher=WebMineral.com|accessdate=July 15, 2015}}{{cite web|url=http://www.mindat.org/min-4020.html|title=Triphylite|publisher=Mindat.org}}{{cite encyclopedia|url=http://rruff.info/doclib/hom/triphylite.pdf |title=Triphylite|encyclopedia=Handbook of Mineralogy |editor1-first=John W. |editor1-last=Anthony|editor2-first=Richard A. |editor2-last=Bideaux|editor3-first=Kenneth W. |editor3-last=Bladh|editor4-first= Monte C. |editor4-last=Nichols |publisher=Mineralogical Society of America|location=Chantilly, VA}}}}

Triphylite is a lithium iron(II) phosphate mineral with the chemical formula LiFePO₄.[http://ima-cnmnc.nrm.se/imalist.htm IMA-CNMNC List of Mineral Names] (May 2015), International Mineralogical Association It is a member of the triphylite group and forms a complete solid solution series with the lithium manganese(II) phosphate, lithiophilite. Triphylite crystallizes in the orthorhombic crystal system. It rarely forms prismatic crystals and is more frequently found in hypidiomorphic rock. It is bluish- to greenish-gray in color, but upon alteration becomes brown to black.