Georgia O'Keeffe, White Shell with Red, 1938, pastel on wood pulp laminate board, 54.6 x 69.8 cm, The Art Institute of Chicago. Source
Here are two gorgeous swirling seashell studies from Georgia O’Keeffe, whose work will be the subject of an exhibition at the Tate Modern later this year. The artist revisited this precise composition a number of other times during her career, but these stand out as my personal favourites. I particularly like the glowing white of the first seashell example, contrasted against the raw red of its mountainous frame.
Georgia O'Keeffe, Pink Shell with Seaweed, c.1938, pastel on board, 55.72 x 70.64 cm, The San Diego Museum of Art. Source