Glas Natur, Struktur und Eigenschaften

Scholze, Henning; Kühne, K.

doi:10.1002/crat.19790140313

Cited by 52 publications

(37 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Iron: Fe in its trivalent state can be responsible for the yellow-brown colour of glass (Scholze 1988;Kurzmann 2003). In the translucent yellow-brown parts of fragments 2 and 29, no colouring agents except Fe were detected.…”

Section: Ionic Colouring Agentsmentioning

confidence: 99%

Chemical composition and colouring agents of Roman mosaic and millefiori glass, studied by electron microprobe analysis and Raman microspectroscopy

Gedzevičiūtė¹,

Welter

Schüssler

et al. 2009

Archaeol Anthropol Sci

View full text Add to dashboard Cite

About 100 fragments of Roman mosaic and millefiori glass were stylistically attributed to a Hellenistic type, a Ptolemaic and Romano-Egyptian period type and an early imperial period type. Twelve representative fragments were studied by electron microprobe analysis and Raman microspectroscopy. Eleven of them display a Napronounced recipe with low K, Mg and P contents, typical for the Roman period. Minor differences in composition are unsystematic, not reflecting the stylistic classification. Ionic colouring agents are Mn 3+ for violet, Cu 2+ for light blue, Co 2+ for deep blue and Fe 3+ for brown translucent colours. Calcium antimonates, lead antimonate and cuprite are the colourants responsible for white, yellow and red colours, respectively, and additionally serve as opacifiers. Mixing of ionic colouring agents and opacifying colourants led to a more differentiated palette of colours. Pb was used as yellow colouring agent, as a flux material and as a stabiliser for the colourant crystals. The remaining fragment consisting of a K-pronounced but still Na-bearing glass matrix was most likely produced during the Middle Ages or later.

show abstract

Section: Ionic Colouring Agentsmentioning

confidence: 99%

Chemical composition and colouring agents of Roman mosaic and millefiori glass, studied by electron microprobe analysis and Raman microspectroscopy

Gedzevičiūtė¹,

Welter

Schüssler

et al. 2009

Archaeol Anthropol Sci

View full text Add to dashboard Cite

show abstract

“…Thus, intensive dusting with B 4 C triggered crystallization of needle-like foreign crystals and caused a rippled surface morphology. These e¬ects can be explained assuming an enrichment of B 2 O 3 in the near-surface area due to oxidation of B 4 C and to the well-known decrease in surface tension by the addition of B 2 O 3 (Scholze 1977). This observation is con rmed by the chemical inertness of B 4 C under vacuum.…”

Section: (F ) Solid Particlesmentioning

confidence: 99%

Recent studies of internal and surface nucleation in silicate glasses

Zanotto

Fokin

2003

Philosophical Transactions of the Royal Society of London. Seri

View full text Add to dashboard Cite

This article reviews recent ndings on internal and surface nucleation in silicate glasses. The internal homogeneous nucleation rates sharply decrease and the induction times increase with the T g =T L ratio (T g is the glass-transition temperature and T L is the liquidus temperature). Only systems that have T g =T L < 0:58 display measurable internal nucleation rates on a laboratory time-scale. Numerous tests of the classical nucleation theory have demonstrated that the theory fails to describe nucleation rates in glasses quantitatively. Possible explanations for this failure are tested and discussed. Surface nucleation depends strongly on the surface quality, e.g. tips, cracks and scratches, elastic stresses, foreign particles and surrounding atmosphere. The mechanisms of surface nucleation are still not fully understood, but some of the key factors are now known and the surface-nucleation density can thus be controlled for the development of sintered glasses or glass ceramics.

show abstract

“…In a different but equally important context, the rich diversity of phosphate mineralogy is matched by a large glassforming range of composition in silicophosphate and phosphate glasses (Scholze, 1988), and indeed P2O5 itself is glassforming. As a result the properties of phosphate glasses and liquids have been investigated (Bansal & Doremus, 1986 The structural role of phosphorus in silicate melts has been the subject of a large number of spectroscopic measurements (see Mysen, 1988, for a review) and it has been demonstrated that phosphorus additions can produce octahedrally coordinated Si in silicophosphate glasses at 1 atm (Sekiya et al, 1988).…”

Section: Introductionmentioning

confidence: 99%

The effect of P2O5 on the viscosity of haplogranitic liquid

Dingwell¹,

Knoche²,

Webb³

1993

ejm

View full text Add to dashboard Cite

: The effect of P2O5 on the viscosity of a haplogranitic (K2O-Na2O-AhO3-SiO2) liquid has been determined at 1 atm pressure in the temperature interval of 700 -1650°C. Viscosity measurements of a haplogranite, haplogranite + 5.1 wt.% P2O5 and haplogranite + 9.5 wt.% P2O5 have been performed using the concentric cylinder and micropenetration methods.The viscosity of haplogranite liquid decreases with the addition of P2O5 at all temperatures investigated. The viscosity decrease is nonlinear, with the strongest decrease exhibited at low P2O5 concentration. The temperaturedependence of the viscosity of all the investigated liquids is Arrhenian, as is the case for P2O5 liquid. The Arrhenian activation energy is slightly lower in the P2O5-bearing liquids than in the P205-free haplogranite with the result that the effect of P2O5 on viscosity is a (weak) function of temperature. At temperatures corresponding to the crystallization of phosphorus-rich granitic and pegmatitic systems the addition of 1 wt.% of P2O5 decreases the viscosity 0.2 logio units.The effect of P2O5 on haplogranitic melt viscosity is much less than that for B2O3, F2O-1 on the same melt composition (Dingwell et al, 1992 and this study). This implies that P2O5 concentration gradients in high-silica melts during, for example, phosphate mineral growth or dissolution in granitic magmas, will not significantly influence melt viscosity.

show abstract

Glas Natur, Struktur und Eigenschaften

Cited by 52 publications

References 0 publications

Chemical composition and colouring agents of Roman mosaic and millefiori glass, studied by electron microprobe analysis and Raman microspectroscopy

Chemical composition and colouring agents of Roman mosaic and millefiori glass, studied by electron microprobe analysis and Raman microspectroscopy

Recent studies of internal and surface nucleation in silicate glasses

The effect of P2O5 on the viscosity of haplogranitic liquid

Contact Info

Product

Resources

About