Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: chrysoprase

Sortuj według:

Ogranicz wyniki do:

Chrysoprase – history and present

Sachanbiński Michał, Kuleba Mirosław, Natkaniec-Nowak Lucyna

Mineralogia

2023

Vol. 54, iss. 1

1--10

The authors present the history of chrysoprase discovery and the progress of knowledge about this material over the millennia, based on the extended review of world literature. Tracing the oldest archaeological artifacts from before 9,000 years, the lens of history turns on a stone that has not been properly identified mineralogically for centuries. In the 1830s, chrysoprase was finally included into the chalcedony group and its green color was associated, very correctly, with nickel compounds dispersed in its structure. After all, the most current mineralogy of chrysoprase is presented on the basis of the results of modern analytical studies. These data clearly indicate that chrysoprase is a mixture of several SiO2 polymorphs with varying degrees of structural order (opal, chalcedony, moganite, quartz). This radically changes the previous taxonomy of chrysoprase and its position in current mineralogical and petrographic systematics.

Studies of chrysoprase and microcrystalline silica varieties from serpentinites of Szklary Massif (Foresudetic Block, SW Poland) by Raman spectroscopic technique – preliminary results

Korybska-Sadło I.

Mining Science

2015

Vol. 22, Special Issue 2

39--45

The mineralogical properties of green colored chalcedony varieties from weathering cover of slightly serpentinized peridotites (harzburgites) occurring near Szklary village on Foresudetic Block (SW Poland) are studied using Raman spectroscopy in the 200 – 1600-1 wavenumber region . The obtained results show, that in examined samples, the peaks like: 206, 265, 355, 394, 464, 696, 796, 808 cm-1, characteristic for α-quartz were ascertained. In one sample, the characteristic moganite peak (502 cm-1) was found. It implies that presence of other polymorphs of SiO2 in crystalline structure, considered a proof for presence of moganite intergrowths with α-quartz. It indicate, that intensity of green color of measured samples of chrysoprase are not correlated with Raman spectroscopic data. It can be conclude, that examination of Raman spectra can be useful only to recognition of internal phase composition of green cryptocrystalline silica polymorphs occurring in weathering cover of serpentinized peridotites.