Ko te Sellaite he kohuke haurua onge noa, e puta noa ana i te taiao, e tautuhia ana e te tātai matū MgF₂. Ko tōna hanganga he ōrite ki te rōpū rutile, ka tioata i roto i te pūnaha tioata tapawhā, ka puta hei tioata kāre he tae, mā, he kōwhai kōmā rānei i ētahi wā, hei kohinga kaikākā, heuheu hoki. Ka whakaatu te kohuke i te kanapa karaihe motuhake, ā, he pakaruhanga tino pai ki ngā papa tīwata {110}, he āhuatanga e wehewehe ai i ngā haurua noa iho. Mō te pūkōwhai, e whakaatu ana te Sellaite i te pakari tinana tino nui, e tata ana ki te 5 ki te tauine Mohs mō te pakeke o te kohuke. I tua atu, he tohu ake nā ngā taupū whakaata tino iti me te āpurearua tōrunga nui. I tua atu i tōna putanga māori, ka mahi te Sellaite hei tauira ā-tāwharao ki te pūkōwhai konupora waihanga, he rauemi tioata e tino whakanuia ana, e hangaia nuitia ana i ngā mahi matawhatu hou. Ko tōna awhe whakawhiti whānui—mai i te tāhikaro tūhāhā ki te pōkākā hōhonu—me te taupū whakaata iti māori, e kore e taea te karo i te whakatairite waihanga mō ngā paninga kiriangi kiriweti motuhake, ngā matapihi taiaho excimer, me ngā pūnaha matawhatu whakangao arotahi.
Ko te tuhinga me te whakaingoatanga o te sellaite i timata mai i te tau 1868, i whai pakiaka hohonu ki te wā taketake o te ao marama o te matawhenua pūtaiao hou. I kitea tuatahitia te kāhanga i te takiwā pukepuke o te rohe o Gava Glacier i Piedmont, Itari, hei whakaurunga tioata rereke i roto i ngā putunga parataiao anhydrite. I whakatauhia te tuatahitanga o tēnei kāhanga hou e Quintino Sella (1827–1884), he tohunga rongonui o Itari nāna i hono motuhake ai ngā mahi uaua o ngā pūtaiao tika me te tōrangapū ā-motu. Ehara a Sella i te tohunga tioata me te ahorangi o te matawhenua anake, engari he kaiwhakahaere kaha hoki i whai wāhi nui ki te whakakotahitanga o Itari. I te mōhio ki te hiranga nui o tēnei kitenga, ko tōna hoa noho, te tohunga matawhenua rongonui a Luigi Bombicci, i whakaingoa ōkawa i te momo “sellaite.” Ko te tikanga o tēnei ingoa he whakanui i te mahi tuatahi a Sella me tana tuhinga tioata pāngarau tika o ngā momo kāhanga o Itari, hei whakau i tōna taonga i roto i ngā pūtaiao whenua me te whakaae ki tōna pānga nui ki te whakaū i ngā taumata mātauranga o te rangahau matawhenua i te rau tau 1800 o Uropi.
Mai i te tirohanga paragenetic, ko te whakaputanga o te sellaite e hiahia ana i nga tikanga matū whenua tino motuhake me te tino whaiti, ko te mea nui ko te whakakiihanga o te fluorine. Ka whakakikoruatia i roto i nga punaha whakaheke waiariki iti-ki-te-waenga e whakawhiti ana i nga papa metamorphic, ina koa ka uru nga waipuke fluorine ki roto i nga toka rangatira o te konupora, penei i te dolomite, i te putunga magnesite ranei. Hei tikanga ke, ka taea e te wai te whakaheke hei kohuke authigenic i roto i nga raupapa whakaetonga o te roto kawa, he nui te wehewehe; i enei taiao tote tino maroke, ka pahekeheke nga wai moana ki te konupora ki nga puna wai fluorine e tino kitea ana. I tua atu, kua tuhia te sellaite hei putunga whakaheke i nga waahi puia e kaha ana, e whakakikorua ana i te wa e tere ana te whakamatao o nga hau whakapuke teitei e rere mai ana i nga fumarole. Ko te herenga nui mo te hanganga o te sellaite ko te hiahia mo te ōwehenga konupora-ki-konupūmā tino teitei i roto i nga waipuke matua. I raro i nga tikanga matū whenua noa, ka kaha te whakaeke a te konupūmā hei puna maori mo te fluorine hei whakaputa i te kohuke fluorite (CaF₂). No reira, ka taea anake te whakaputa sellaite i nga taiao e tino whakahekehia ana, e pumau ranei te konupūmā, kia taea ai te takirua onge o te konupora kukū me te fluorine karekau ki te whakatutuki i te pūmautanga thermodynamic me te whakakikorua.
Te wāhi me te putanga
Ko Sellaite i tautuhia tuatahi i tona waahi momo e tata ana ki te awaawa o Gava i te rohe o Piedmont o Itari, i kitea ai i reira e mau ana i roto i nga papa nui o te anhydrite. I tua atu i tenei kitenga taketake i roto i te horanga evaporite alpine, kua tuhia nga putanga nui o te ao puta noa i nga taiao whaikiko motuhake me te kanorau matū whenua. Ko enei ko nga papatipu toka pāpāho alkaline o te Kōra Peninsula i Rūhia, e rongonui ana mo te nui o te halogen me nga huānga hotokore. Ko nga ahuatanga matū whenua rite te kaihautu i te sellaite i roto i nga huinga toka whakarewa e hono ana ki te evaporite o te Siberian Murun Massif. I Amerika ki te Raki, kua kitea etahi tauira tino pai te whakapapa, e tika ana te hanganga, mai i te whare whakauru alkaline o Mount Saint-Hilaire i Quebec, Canada, he taiao e rongonui ana mo ana wai pegmatitic tino whai kiko, tino kaha. I tua atu, kei te kitea te sellaite hei waahanga tuarua i roto i nga putunga potash o Bleicherode o te wā Permian i Tiamana, e whakaatu ana i tona piri ki nga taiao tote tino wehewehe. He mea whakamiharo, ka puta ano ia i raro i nga ahuatanga wera rereke hei whakaheke fumarolic motuhake i nga waahi puia kaha, ka tīmata tika mai i nga haurehu halogen wera mai i te Maunga Vesuvius i Itari me te puia o Kudriavy i nga Moutere Kuril.
Ngā Momo me ngā Whakarōpūtanga
Hei momo kohuke rerekē te hanganga, kāore te sellaite e mau ana i ngā momo iti ahurei matū, i ngā rerekētanga hanganga rānei e mōhiotia whānuitia ana. I runga i te mātauranga kohuke, ka whakarōpūtia tōtika ki raro i ngā taiohi hauhā korewai o roto i ngā anga whakarōpūtanga pūnaha a Dana me Strunz. Heoi, nā te mea ko tōna whakaaturanga tonotono me ngā nekehanga tipu tioata e whakatauhia kaha ana e tōna taiao hanga motuhake, ka whakarōpūtia ngā tauira sellaite i runga i te āhua i runga i ō rātou āhuatanga taiao motuhake. Ko ēnei rerekētanga hanganga e whakaatu ana i te mahana, te pēhanga, me te whakaurunga o ngā wai matua.
- Ahua Waiariki: Ko te āhuatanga o ngā tioata tapatoru e kitea whānuitia ana, e whai āhua pai ana, e whakaheke mai ana i ngā wai e tino whanawhanau ana, e mātao haere ana i roto i ngā pūnaha kōaka waiariki. Ko ēnei tioata e whakaatu ana i ngā mata e tino mārama ana, me te mārama o te titiro e teitei ake ana.
- Ahua toka whakaetonga: Ka tautuhia e ngā whakahuihui kirikiri moroiti matotoru, whai kiko, kāpō rānei. Ko tēnei āhua ka puta i roto i ngā papa whakaeto matatū konupūmā tino whāiti, i reira ko te whakaparahako tere mai i ngā wai tote moana tino totea e ārai ana i te tipu o ngā tioata nui, motuhake.
- Ahua Fumarole E whakatūturu ana i ngā pōro mātotoru, ngā pōro pūare rānei e whakaputa ana i te mata. Ka tino whakataetae ēnei hanganga i te wā e tere ana te whakamātao me te whakaheke i te pēhanga o ngā hau pūngāwhā e pā ana ki ngā āhuatanga o te rangi.
Hanganga Karaihe
Ka tio te sellaite i roto i te pūnaha tio tapawhā, e noho ana i te rōpū mokowā tino hangarite P4₂/mnm. Ko tōna hoahoanga tio he tino rite ki tō te rutile (TiO₂), he whirihoranga e whakaawe nui ana i tōna pūmau ā-tinana whakahirahira. I roto i tēnei whirihoranga matatini tika, e ruruku ana ia katio nākonu waenga (Mg²⁺) e ono ngā pūtoru pākōwhai (F⁻) e noho ana i ngā tohu o te oktahedrona paku kōiwi. Heoi, e karapotia ana ia pūtoru pākōwhai e toru ngā katio nākonu i roto i te āhua tata papatahi toru-ruruku. Ka tiritiri ngā oktahedrona MgF₆ taketake i ngā tapa whakapae whakapae ki te hanga i ngā mekameka raina whakarara pakari e toro tonu ana i te tuaka-tio c. Ka hono atu ēnei mekameka whakarara mā te tiritiri i ngā pūtohu o runga ki ngā mekameka tūtata, ka hua ai he anga āhuahanga toru-ahu pūtohu, kikī. Ko tēnei kikīnga ngota, me ngā here katote kaha i waenga i ngā katote nākonu me pākōwhai iti, e tohu tika ana i te pūngao matatini tiketike me te mārō o te kōhura i whakaritea ki ētahi atu haraidī ngāwari.
Ngā Āhuatanga Tinana me te Matū
Mai te tirohanga whakauru me te tūwhera pūngao, ko te sellaite he haurua kore wai tino pūmau, e 39.0% te konupora, 61.0% te fluorine i te taumaha. He tino koretake, he iti te whakarewa ki te wai, ā, he kaha te ātete ki te nuinga o ngā waikawa mātao. I te taha tinana, e 5 te mārō i te tauine Mohs—he mārō rawa atu mō te kohuke pūkōura, e 2 ki te 4 te nuinga—ā, e 3.15 g/cm³ te kiato e tata ana. E whakaatu ana te kohuke i te māwāwāwe tino pai i te paparangi {001} me te māwāwāwe tūāpapa i te {110}, e mārō ana i raro i te taumahatanga ā-pūkaha. I te taha whakamārama, he uniaxial positive te sellaite, ā, e mōhiotia ana mō te iti rawa o ngā taurangi whakaata (n_ω ≈ 1.378, n_ε ≈ 1.390) me te iti rawa o te whakaata-ārua. Nā tēnei korenga o te whakaata nui, te wehenga rānei, e tata ana ki te isotropic i raro i te marama whakawhiti-pou, e kitea ana he ōrite te hanga. I ngā tauira ringaringa nui, e kore e kitea he tae, he mā rānei, engari mā ngā poke iti e whakaputa ai i te pūhinuhinu noa o te kiwikiwi, te kōwhai hina rānei, me te kanapa karaehe ki te kanapa hinu iti e whai ana.
Whakamahinga me te Whakamahi Ahumahi
Ahakoa he tino onge a sellaite māori i te matawhenua kāore e taea te keri arumoni, te whakamahi rānei i te nui, ko tōna hoa whakahāngai, te pākareta konupora (MgF₂), he rawa tino nui i roto i te ao whakaata matatau, te photonics, me te hangarau rawa. E whakatauhia ana e tōna taupātanga whakaata tino iti, te āputa whakahaere hiko nui, me te hihinga whakawhiti whakaata tino nui e hora ana mai i te ultraviolet korehāhā hōhonu (120 nm) ki te pōkākā waenga (8.0 μm), ko te MgF₂ whakahāngai te paerewa ahumahi mō ngā paninga whakaata kiriata angiangi. Ka whakatakotorangia mā te whakaheke tinana korehāhā (PVD) hei paninga whakaata whakahoki whānui whānui mō ngā mea whakaata tino tika, ngā kāmera whakaahua taumata teitei, ngā telescope arorangi, me ngā panui photovoltaic whaihua nui hei whakaiti i te whakaata mata me te whakanui i te whakawhiti mārama. Waihoki, ko ngā puāwai tioata pakari i hangaia ki te hanganga sellaite e mahi ana hei matapihi whakaata tino nui mō ngā laser excimer hiko nui me ngā wāhanga whakamātau tairongo i roto i ngā taputapu ātea-rangi. I tua atu i te whakaata matatau, ko tēnei hei kaiāwhina whakarewa whaihua, pūmau i roto i te tukatuka whakarewa o te konupora me ngā koranu konumohe matatau, e āwhina ana ki te whakaheke i te pāmahana whakarewanga me te tango paru mai i te whakarewa rewa.