{"id":5687,"date":"2024-12-06T21:06:43","date_gmt":"2024-12-06T19:06:43","guid":{"rendered":"http:\/\/www.e-gems.cz\/?post_type=kamen&#038;p=5687"},"modified":"2025-03-21T12:51:46","modified_gmt":"2025-03-21T10:51:46","slug":"sekaninait","status":"publish","type":"kamen","link":"https:\/\/www.e-gems.cz\/en\/kamen\/sekaninait\/","title":{"rendered":"Sekaninait"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\">Historie<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Modrofialov\u00fd cordierit je atraktivn\u00ed drahokamov\u00fd materi\u00e1l dostupn\u00fd za velmi p\u0159ijateln\u00e9 ceny. Cordierit je koncov\u00fdm \u010dlenem \u0159ady cordierit \u2013 sekaninait, p\u0159i\u010dem\u017e druh\u00fd jmenovan\u00fd miner\u00e1l je podstatn\u011b vz\u00e1cn\u011bj\u0161\u00ed. V posledn\u00edch n\u011bkolika letech se na typov\u00e9 lokalit\u011b sekaninaitu, Doln\u00ed Bory v \u010cesk\u00e9 republice, objevilo d\u00edky aktivit\u00e1m sb\u011bratel\u016f miner\u00e1l\u016f n\u011bkolik exempl\u00e1\u0159\u016f drahokamov\u00e9 kvality. Tyto drahokamy maj\u00ed \u0161edomodrou a\u017e modrofialovou barvu s velmi siln\u00fdm pleochroismem, jak je b\u011b\u017en\u00e9 u cordieritu.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Sekaninait je vz\u00e1cn\u00fd sb\u011bratelsk\u00fd drah\u00fd k\u00e1men, av\u0161ak ve \u0161perku je t\u00e9m\u011b\u0159 vylou\u010den\u00e9 se s&nbsp;n\u00edm setkat.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Vlastnosti<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Chemick\u00fd vzorec \u0159ady cordierit \u2013 sekaninait je (Mg,Fe<sup>2+)<\/sup><sub>2<\/sub>Al<sub>3<\/sub>(AlSi<sub>5<\/sub>O<sub>18<\/sub>) \u2013 (Fe<sup>2+<\/sup>Mg)<sub>2<\/sub>Al<sub>3<\/sub>(AlSi<sub>5<\/sub>O<sub>18<\/sub>); oba miner\u00e1ly jsou komplexn\u00ed cyklosilik\u00e1ty Mg, Fe a Al krystalizuj\u00edc\u00ed v ortorhombick\u00e9 soustav\u011b. Existuje tak\u00e9 vysokoteplotn\u00ed hexagon\u00e1ln\u00ed dimorfikace cordieritu zvan\u00e1 indialit, Mg<sub>2<\/sub>Al<sub>3<\/sub>(AlSi<sub>5<\/sub>O<sub>18<\/sub>), kter\u00fd je izostrukturn\u00ed s&nbsp;berylem. Sekaninait z Doln\u00edch Bor\u016f byl jako nov\u00fd miner\u00e1l pops\u00e1n v&nbsp;70. letech 20. stolet\u00ed J. Sta\u0148kem a J. Mi\u0161kovsk\u00fdm; pojmenov\u00e1n byl na po\u010dest \u010desk\u00e9ho mineraloga Dr. Josefa Sekaniny (1901\u20131986).&nbsp;<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">V\u00fdskyt<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Na\u0161e nab\u00edzen\u00e9 sekaninaity drahokamov\u00e9 kvality byly nalezeny v oblasti Hat\u011b, p\u0159ibli\u017en\u011b 8 km severn\u011b od Velk\u00e9ho Mezi\u0159\u00ed\u010d\u00ed a 1,5 km z\u00e1padn\u011b od Doln\u00edch Bor\u016f na Vyso\u010din\u011b. Tento b\u00fdval\u00fd t\u011b\u017eebn\u00ed prostor se nach\u00e1z\u00ed v lesn\u00edm porostu mezi \u0159ekou Oslavou a obc\u00ed Doln\u00ed Bory, ji\u017en\u011b od potoka Baba\u010dka. V t\u00e9to oblasti moldanubick\u00e9ho komplementu na severn\u00edm okraji borsk\u00e9ho granulitov\u00e9ho masivu je zn\u00e1mo p\u0159ibli\u017en\u011b 20 pegmatit\u016f, sekaninait byl v\u0161ak nalezen pouze na n\u011bkolika z&nbsp;nich.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Nejv\u00fdznamn\u011bj\u0161\u00ed akumulace byly na b\u00fdval\u00e9m \u017eivcov\u00e9m dolu MKZ (MKZ = Moravsk\u00e9 keramick\u00e9 z\u00e1vody). Sekaninait je obvykle uzav\u0159en v ortoklasu (a albitu), kter\u00fd byl hlavn\u00ed surovinou t\u011b\u017eebn\u00edch provoz\u016f. Ortoklas se zde ru\u010dn\u011b t\u0159\u00eddil a pou\u017e\u00edval pro keramick\u00fd pr\u016fmysl; t\u011b\u017eba ortoklasu v mal\u00e9m m\u011b\u0159\u00edtku za\u010dala ji\u017e v roce 1887 a po druh\u00e9 sv\u011btov\u00e9 v\u00e1lce se za\u010dalo s hlubinnou t\u011b\u017ebou, kter\u00e1 skon\u010dila v&nbsp;roce 1972.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Historie Modrofialov\u00fd cordierit je atraktivn\u00ed drahokamov\u00fd materi\u00e1l dostupn\u00fd za velmi p\u0159ijateln\u00e9 ceny. Cordierit je koncov\u00fdm \u010dlenem \u0159ady cordierit \u2013 sekaninait, p\u0159i\u010dem\u017e druh\u00fd jmenovan\u00fd miner\u00e1l je podstatn\u011b vz\u00e1cn\u011bj\u0161\u00ed. V posledn\u00edch n\u011bkolika letech se na typov\u00e9 lokalit\u011b sekaninaitu, Doln\u00ed Bory v \u010cesk\u00e9 republice, objevilo d\u00edky aktivit\u00e1m sb\u011bratel\u016f miner\u00e1l\u016f n\u011bkolik exempl\u00e1\u0159\u016f drahokamov\u00e9 kvality. Tyto drahokamy maj\u00ed \u0161edomodrou a\u017e [&hellip;]<\/p>\n","protected":false},"featured_media":7608,"template":"","meta":{"_acf_changed":false,"inline_featured_image":false},"class_list":["post-5687","kamen","type-kamen","status-publish","has-post-thumbnail","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.e-gems.cz\/en\/wp-json\/wp\/v2\/kamen\/5687","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.e-gems.cz\/en\/wp-json\/wp\/v2\/kamen"}],"about":[{"href":"https:\/\/www.e-gems.cz\/en\/wp-json\/wp\/v2\/types\/kamen"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.e-gems.cz\/en\/wp-json\/wp\/v2\/media\/7608"}],"wp:attachment":[{"href":"https:\/\/www.e-gems.cz\/en\/wp-json\/wp\/v2\/media?parent=5687"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}