The Lapis Lazuli Portrait In Italian Free Download ##VERIFIED##
The Lapis Lazuli Portrait In Italian Free Download >>> https://geags.com/2t7Q2G
All images and data available through Open Access can be downloaded for free. For images not available through Open Access, a detail image, or any image with a color bar, request a digital file from Image Services.
Matching micro-Raman spectra are produced by archaeological blue particles and lazurite crystals in reference pigments from both modern lapis lazuli and a blue pigment from a medieval fresco painting that was previously identified as lapis lazuli (21). Inset: Optical image of archaeological blue particle. Raw data are provided in data file S3. Credit: A. Radini, E. Tong, R. Kröger.
Matching micro-Raman spectra of the colorless particle and a published reference spectrum of phlogopite (23), an accessory mineral that co-occurs with lazurite in natural lapis lazuli stone. Inset: Optical image of archaeological colorless particle. Raw data are provided in data file S3. Credit: A. Radini, E. Tong, R. Kröger.
Abstract:The blue color of glass and ceramic glazes produced in Apulia and Basilicata (Southern Italy) between the 13th and 14th centuries and connected to the Norman-Swabian Emperor Frederick II, has been, for a long time, under archaeometric investigation. On the one hand, it has usually been associated with lapis lazuli, due to the finding of the polysulphide blue chromophores typical of lazurite. Moreover, the observation that the mineral haüyne, which belongs to the sodalite group as well as lazurite, can be blue and/or can gain a blue color after heating, due to the same chromophores, has caused this automatic attribution to be questioned, and also considering that the mineral is characteristic of the rock haüynophyre of Melfi (Potenza, Southern Italy), a location of interest for glass and pottery findings. In this paper, for the first time, several haüyne crystals were found in the blue glaze of a ceramic dish found at Melfi Castle, leading to the hypothesis that, in this case, the local haüyne-bearing source could have been used as the coloring raw material. The discovery was possible thanks to SEM-EDS and Raman analyses that, respectively, highlighted the typical numerous presence of very fine sulphur-based inclusions in the crystals and the characteristic Raman signal of blue haüyne. This study was also focused on the composition of the crystals inclusions, aided by SEM-EDS and Raman maps, since the original very fine pyrrhotite was transformed into Cu and Pb phases (copper sulphates, copper sulphides, and lead oxide) due to reactions with cations that had mobilized from the glaze, while the migration of Si from the glass allowed the transformation of the rim of the haüyne, a silica-undersaturated mineral, into a corona of small euhedral and neomorphic Pb-rich feldspars, a silica-saturated phase.Keywords: blue; lapis lazuli; haüyne; medieval blue tin-lead glazed ceramic; Frederick II
Azurite is a soft, deep-blue copper mineral produced by weathering of copper ore deposits. During the early 19th century, it was also known as chessylite, after the type locality at Chessy-les-Mines near Lyon, France.[3] The mineral, a basic carbonate with the chemical formula Cu3(CO3)2(OH)2, has been known since ancient times, and was mentioned in Pliny the Elder's Natural History under the Greek name kuanos (κυανός: "deep blue," root of English cyan) and the Latin name caeruleum.[5] Since antiquity, azurite's exceptionally deep and clear blue has been associated with low-humidity desert and winter skies. The modern English name of the mineral reflects this association, since both azurite and azure are derived via Arabic from the Persian lazhward (لاژورد), an area known for its deposits of another deep-blue stone, lapis lazuli ("stone of azure").
The laser system is based on pump-probe spectroscopy. It is an imaging technique that shoots two laser pulses through a series of lenses and mirrors and into a custom-built microscope. A tiny sample of a painting, or in the case of The Crucifixion, the entire piece, sits on the stage of the microscope. The pulses are timed so that the pump pulse excites the molecules at the focal point of the microscope's lens. Then, after a billionth of a millisecond delay, the probe pulse hits the same pigment. The intensity of the probe pulse will change depending on its interaction with the excited pigment molecules. The change in intensity over time of the probe pulse gives each pigment a unique pump-probe signature, says Tana Villafaña, a Duke graduate student who works on the project. She says one of the clearest signatures the team has identified is from the aquamarine pigment lapis lazuli. Artists originally made this pigment from a relatively rare, semi-precious stone. The stone is ground, then the lapis pigment extracted through a process of mashing the coarse grind under water in a ball of wax and resin. The purified pigment is then tempered with egg yolk and water to the right right consistency and gloss for brushing it onto a canvas. 2b1af7f3a8