Chalcedony

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Chalcedony
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Batu chalcedony
Umum
KategoriMineral oksida
Rumus kimiaSilika (silikon dioksida, SiO2)
Identifikasi
Massa molekul60 g / mol
Warnamaneka werna
Skala kekerasan Mohs6 - 7
Berat jenis2.59 - 2.61
Referensi[1]

Chalcedony /kælˈsɛdəni/ inggih menika satunggaling wujud ingkang sami tumpuk-tumpukan.[2] Kuarsa lan moganit menika kalebet mineral silika, ananging kuarsa menika gadhah pérangan trigonal wondéné ingkang moganit menika gadhah sipat ingkang monoklinik. Struktur kimia saking chalcedony inggih menika SiO2.

Nama chalcedony menika asalipun saking basa Latin chalcedonius (utawi calchedonius). Istilah menika ingkang kaping sapisan wonten ing satunggaling karyanipun Pliny the Elder, Naturalis Historia ingkang dipun-ginakaken kanggé nyebat batuan Jaspis ingkang asipat transparan.[3]Chalcedon ingkang wonten ing Asia Cilik.[4] Ananging istilah khalkedon (χαλκηδών) menika ugi medal wonten ing Book of Revelation.[5]

Geokimia[besut | besut sumber]

Struktur[besut | besut sumber]

Chalcedony menika naté dipunwastani minangka kriptokristalin kuarsa ingkang gadhah kandhutan serat[6] ananging samenika dipunmangertosi bilih chalcedony menika ugi gadhah sipat ingkang polimorf amargi wonten moganit wonten ing salebeting chalsedony kasebat.[2][7][8] Kadar moganit ing satunggal sampel chalcedony manéka werna, Padatanipun ing antawisipun 5 dumugi 20 persèn.[9]

Kelarutan[besut | besut sumber]

Sinaosa gadhah senyawa kimia ingkang mèmper kaliyan kuarsa, ananging chalcedony menika gadhah sipat langkung larut tinimbang kaliyan kuarsa wonten ing tèmperatur ingkang andhap. Bab menika saged amargi kristal chalcedony menika langkung alus satemah gadhah rasio wiyaring permukaan lan volume ingkang langkung inggil ingkang dipunprakirakaken amargi wontenipun moganit.[9]

Rujukan[besut | besut sumber]

  1. Rudolf Duda and Lubos Rejl: Minerals of the World (Arch Cape Press, 1990)
  2. a b Heaney, Peter J., 1994. Structure and Chemistry of the low-pressure silica polymorphs. In: Reviews in Mineralogy v. 29; Silica: Physical Behavior, geochemistry and materials applications. Ed. Heaney, P.J., Prewitt, C.T., Gibbs, G.V., 1-40
  3. Pliny the Elder: Naturalis Historiae, Book 37, chapter 7,115 (
  4. Erika Zwierlein-Diehl: Antike Gemmen und ihr Nachleben. Berlin (Verlag Walter de Gruyter) 2007, S. 307 (online) According to the OED a connection with the town of Chalcedon is "very doubtful":Harper, Douglas. "Chalcedony". Online Etymology Dictionary.
  5. James Orr, èd. (1915). "Chalkēdōn". The International Standard Bible Encyclopaedia. The Howard-Severance company. kc. 2859.
  6. Chalcedony mineral information and data. http://www.mindat.org/min-960.html
  7. Origlieri, Marcus. "Moganite: a New Mineral -- Not!" Lithosphere (1994). Aug. 2007 <http://fgms.home.att.net/moganite.htm Archived 2008-03-09 at the Wayback Machine.>.
  8. Nickel, Ernest H., and Monte C. Nichols. "IMA/CNMNC List of Mineral Names." Materials Data. June 2007. Aug. 2007 <http://www.geo.vu.nl/users/ima-cnmmn/MINERALlist.pdf Archived 2008-05-30 at the Wayback Machine.>
  9. a b Heaney, Peter J., and Jeffrey E. Post. "The Widespread Distribution of a Novel Silica Polymorph in Microcrystalline Quartz Varieties." Science ns 255 (1992): 441-443. JSTOR. Aug. 2007. Keyword: moganite

Pranala njawi[besut | besut sumber]