Medici porcelain

Medici porcelain was the first successful attempt in Europe to make imitations of Chinese porcelain. The experimental manufactory housed in the Casino of San Marco in Florence existed between 1575 and 1587 under the patronage of Francesco I de' Medici, Grand Duke of Tuscany. A painted mark of Brunelleschi's dome and a capital letter F appear on the underside of some pieces; others bear the Medici palle, the balls that are the Medici heraldic charge. Never a commercial venture, Medici porcelains were sometimes given as diplomatic gifts; for example, surviving pieces bear the arms of Philip II of Spain.

Giorgio Vasari reported in the 1568 edition of his Vite that Bernardo Buontalenti was currently at work on discovering the art of porcelain, but there is no sign that he was successful. The first successes were finally reported in 1575 by the Venetian ambassador Andrea Gussoni, who mentioned in his brief to the Serenissima that Francesco discovered the means of making "the porcelain of India," (i.e. the East Indies). Gussoni mentioned in particular the four qualities that made porcelain desirable, apart from its exotic rarity:

However, the entire project was ultimately relatively short-lived; the high-firing temperature pushed sixteenth century technical capability to its limit, resulting in exorbitant production costs. There are no references to Medici porcelain manufacture securely dated after Francesco's death in 1587.

The body of Medici porcelain ware is a type of soft-paste porcelain, composed of white clay containing powdered feldspar, calcium phosphate and wollastonite (CaSiO3), with quartz. The glaze contains calcium phosphate, indicating that the middle-eastern technique of using calcined bone to make an opaque white glaze was adopted. The result is translucent but slightly glassy in feel. Following the precedents of classic Chinese blue and white porcelain, decorations were painted in underglaze blue, which resulted in a range of hues when fired—from a bright cobalt blue (such as a flask in the National Gallery of Art) to grey (such as the bottle detail at right). Some pieces have outlines traced in manganese.

...
Wikipedia