Rosettes

A n-pointed rosette is formed by a n-pointed regular star, usually with 2 layers, surrounded by n identical hexagons called petals. 

A petal fits between two sides adjacent to an interior vertex of the regular star.

A petal is symmetrical about the line that passes through its outermost vertex and the center of the star.

Convergent, parallel and divergent rosettes

If, when extending outward, the two lateral sides of any petal of a rosette converge, are parallel or diverge, we say that the rosette is convergent, parallel or divergent, respectively.

Parallel and convergent rosettes are the most common in Islamic art.

The shape of the petals

The length of the petals is not determined by the geometry of the base star and depends on the designer's taste or the needs to fit when the rosette is part of a larger composition.

Longer petals are usually used for high n values, so that the tips of the petals are far enough apart to be more easily visible.

Regular, standard and ideal rosettes

A rosette is said to be regular if the two sides adjacent to the vertex of the petals are part of the outline of a regular polygon with the sides concentric with the rosette.

A rosette is said to be standard if the four outer sides of a petal are of the same length.

A rosette is said to be ideal if it is both regular and standard.

Ornamentation of a rosette

It is customary to decorate the outside of a rosette by extending its sides, intersecting them and connecting the found intersection points. The following figures show different levels of ornamentation of the same rosette.

Coloring of a rosette

Rosettes and its extensions have different aesthetic qualities depending on whether they are represented by lines or in the form of a mosaic coloring the different layers.