Lapis Lazuli Chemical Structure Lapis Lazuli Scanning Electron Microscope - Leonardo Da Vinci, the Energy Dispersive Spectra Virgin of the Rocks, C
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Lapis Lazuli Chemical Structure Lapis Lazuli Scanning Electron Microscope - Leonardo da Vinci, The Energy Dispersive Spectra Virgin of the Rocks, c. Ultramarine • Oltremare • Lazurite (SEM-EDS) 1491, oil on poplar (Italian for Ultramarine) (Name of Mineral) ● In SEM-EDS analysis, electrons are sent in at the Michelle Tremblay and Mitchell Famulare sample and x-rays are given off Paint Cross Section from the ● SEM-EDS analysis has proved that Perugino applied sky. The bottom layer lapis lazuli using the “true fresco” technique in The consists of azurite and lead Origins of Lapis Lazuli Baptism of Christ in the Sistine Chapel white and the second layer ● Lapis Lazuli came from the ancient ● The lapis lazuli was found between the sky and the consists of natural quarries of Badakhshan (modern day frame ultramarine and a little lead (Na,Ca) (AlSiO ) (SO ,S,Cl) Afghanistan) 8 4 6 4 2 white. ● Today there are four known Lapis Ultramarine Sickness Lazuli mines in the Kerano-Munjan valley located at Chilmak, Dilute mineral acids (dilute HCl, HNO or H SO ) 3 2 4 Shaga-Darra-i-Robat-i-Paskaran, rapidly destroy the blue color with evolution of Stromby and Sar-i-Sang hydrogen sulphide gas ● Badakhshan produced practically all the Lapis Lazuli used in Europe 2 H+ + S2- → H S Pietro Perugino, The Baptism of (aq) (aq) 2 (g) ● Lapis Lazuli was imported into Europe Christ, c. 1482, fresco by way of Venice, a principal port city ● Da Vinci’s piece serves as ● In Venice Lapis Lazuli would have Ultramarine was not commonly used from acid from lapis an excellent example of buon fresco mainly because of the cost been sold by vendecolori (color sellers) how ultramarine rather than spezieri da grosso but also because of the possibility of responds to oil paint. Lapis Lazuli Quality damage to the silicate structure (SiO ) The quality and grade of the lapis lazuli pigment has (apothecaries) 4 Detail showing the degradation of ● It is known that depending on how long it is in contact to do with the impurities in the lapis lazuli mineral. Processing Lapis Lazuli ultramarine on the angel’s drapery ultramarine is sensitive Herrmann, Georgina. “Lapis Lazuli: The Early Phases of Its with the calcium hydroxide The main type of impurity found in lapis lazuli are Trade.” Iraq, Vol. 30, no. 1, 1968, pp. 21–57. revealing a reddish brown under layer. to acidic conditions. “Here begins the practice of extracting the azure from the lapis ● when acids dissolve into calcite crystals. Other metallic appearing impurities lazuli...Take the stone, which is a mineral, and after washing it with ley, the air they interact with are iron pyrites or “fool’s gold.” heat it on burning charcoal, and afterwards extinguish it in good and Characteristics of Lapis Lazuli the sulfides in very strong white vinegar...Choose the good pieces, and grind them The lazurite mineral stone provides a very deep violet blue ultramarine to create a Calcite Crystals fine in a brass mortar...when very finely ground put the powder into an color. The first extractions of the stone provide the best high yellow color earthen dish and pour over it hot water or hot ley with a little honey quality pigment. However, when ground to finely, the deep ● The oil paint provides a and clay, rubbing the azure with your hands or with a stick, in order to blue color is lost, leaving ultramarine ash. Ultramarine ash different dilemma. Since extract the refined azure...Afterwards strain it through a linen cloth into comes from the final extractions of the stone, providing a very ultramarine was applied a well-glazed earthenware basin, and pour off the water, or, still better, pale blue color. Often in paintings, different grades of as an extremely thin the ley, leaving the powder of the lapis lazuli settled in the basin; wash ultramarine would be used. Lower grades were far cheaper glaze, during its drying the azure...until the saline particles of the ley are washed away, and let than the very high quality deep blue grades of ultramarine. The Paint cross section from the Virgin’s process it cracked in the azure dry in the shade...” ash provided a means for attaining a fine pale blue color at a blue cloak (neckline) → this shows the several areas. This -Bolognese Manuscript, 15th century, author unknown, taken from Medieval and reasonable cost. extent of ultramarine blanching in the occurs because the lapis Renaissance Treatises on the Arts of Painting by Mary P. Merrifield surface layer. Notice how the color is interacts with the Calcite is a rock form of calcium carbonate protein-like bands of the dull and contains a white coat. CaCO3 oil binder in a way that causes it to degrade. Andrea del Verrocchio, The Virgin Distinguishing Lapis Lazuli and Child with Two Angels, c. Pietro Perugino, The Virgin and Child with an Angel, c.1496-1500, from other blues 1467-9, tempera on wood oil with some egg tempera on poplar Heat Resistance ● The blue color of ultramarine remains unchanged, Tempera and Lapis Egg tempera is the essential whereas azurite is converted to black copper oxide medium for ultramarine. When ● This distinguishes ultramarine from azurite ultramarine dries in tempera, where the binder is egg yolk, it Refractive Index does not crack. Instead it holds ● Refractive light is how light bends as it goes through the onto its deep royal blue color. material However when lead white is mixed ● The RI of lapis is lower than all other pigments at 1.5 with ultramarine in tempera, it ● Different crystals bend light in different ways → this affects reduces its saturation, seen in Cima, The Incredulity of Saint Thomas, c. 1502-4, oil on poplar what we see Ambrogio Bergognone, The Virgin and Child with Saint Catherine of Verrocchio’s piece. In oil, when Cima’s piece provides a perfect example of the use of different Alexandria and Saint Catherine of Siena, lead white is added, the intensity of grades of ultramarine. Cima painted a lower grade of ultramarine Paint cross section from the Virgin’s robe c. 1490, oil on poplar the blue is increased. over a layer of azurite and lead white for the sky. He used the same with ultramarine and lead white at the Polarized-Light Microscopy combination for the robe of St. Peter except with a higher grade of surface over a discolored ultramarine ● When viewed under polarized light, less light is let in Ultramarine, due to its high cost, was primarily used for the drapery of the Paint cross-section of the Virgin’s blue ultramarine. This makes sense that a more expensive grade be glaze. A layer of azurite is seen at the ● Polarized-light microscopy is used to study the structure of Virgin or Christ. It was a convention to paint the Virgin and Christ in the cloak showing a thick layer of used for a robe of a Saint rather than the color of the sky. bottom layer. the pigment particles most expensive material. This is an example of color iconography. ultramarine and lead white over the ● Can differentiate between different structures based on This is one of the best preserved examples of ultramarine bound in oil. gesso(the basis for tempera ) ● Perugino’s use of oil as a medium in this how they interact with the polarized light Infrared image of Titian’s Bacchus and Ariadne taken piece shows a very convincing means of Titian, Bacchus and Ariadne, c. 1520, oil on canvas before cleaning and restoration expressing the volume and quality of Sebastiano del Piombo, The Daughter of Herodias Cost fabrics as well as a more effective way of or Salome, c. 1510, Oil on wood modelling. “More expensive than gold” ● Modelling is a technique where the -The National Gallery, London The drapery contains a layer of azurite(a cheaper blue pigment) painter shows shadow and light by with lead white. On top of this is switching values of color. Another form a thick glaze of ultramarine in of modelling is known as cangiante or > oil. The midtones are painted in hue shift, where the painter shifts to a finely-ground, high quality totally different color when producing ultramarine. The paint in this shadows/highlights. The prices of the pigments of ultramarine and azurite depended on piece is laid so thickly that it ● Differing from tempera paint where the the quality of the raw materials harnesses a three dimensional binder is egg yolk, oil paint allows the and the way they were refined quality rather than a drapery of layering of paint in order to convey of intense color. different shades of color. Thus, the Azurite pigments must show a degree of 40-400 soldi per pound translucency. Less valuable types could cost 24-60 soldi per pound Ultramarine Damage in The Virgin and Child with an Angel 1400s → 940-5,500 soldi per pound Natural lapis lazuli is the most predominant blue pigment in this piece. It is The infrared photography of this image shows the Natural ultramarine/lapis was used for the blue draperies in this painting. The 1500s → 5,000-16,800 soldi per pound mixed with lead white in the sky, the highlights and midtones of blue abundance of pure ultramarine. Ultramarine reflects The ability of oil to produce convincing high saturation of the blue attends to why it was a pigment of choice adding to draperies, the distant landscape, and some of the flowers. In the blue cloak infrared light, meaning that it appears white under it. So images of fabric are exploited in this piece.