What is the primary characteristic of Raphael's works?

The primary characteristic of Raphael's works is indeed the clarity of form and ease of composition. Raphael, a central figure of the High Renaissance, is renowned for his masterful ability to combine naturalism with idealism. His artworks often display a harmonious balance and a calm portrayal of figures that contribute to an overall sense of order and serenity.

In paintings like “The School of Athens” and his numerous Madonnas, the clarity of form can be seen in the well-defined outlines and proportions of the subjects, along with the logical arrangement of space within the composition. This clarity allows viewers to easily understand the narratives being depicted and enhances the overall aesthetic experience.

The other options highlight techniques or styles that are not characteristic of Raphael's body of work. Intricate mosaics are more associated with Byzantine art, dark colors and shadow emphasis point towards the styles of artists like Caravaggio or Leonardo da Vinci, and abstract elements are not generally representative of Raphael, who focused more on realistic forms and grounded subjects. Therefore, the clarity of form and ease of composition stand out as defining traits of Raphael's artistic achievement.