The hard stones are minerals that have the characteristic of being very durable and also very beautiful. The hard stones were used since ancient times for creating objects as diverse as seals, cameos, vases, sculptures and found their use in architecture. Famous are the arches 

of the basilica of Saint Sabina in Rome, the floor of the basilica of Saint Sofia in Constantinople, to thePrinces' Chapel in Florence. This has made ​​examples of Florentine inlay made ​​with semiprecious stones. In this category you will find miniatures and illuminated manuscripts, reproductions of ancient texts that is, mostly on parchment, whose initial letters are traditionally made ​​with images of red and later colored. From the fourteenth century with the spread of small-format illustrations of the term also includes miniature paintings and objects of small size.