An overview of the visionary Dutch expressionist's luminous artwork. In less than two decades, Jacoba van Heemskerck (1876-1923) created a powerful oeuvre comprising paintings, woodcuts, glassworks, and mosaics. Her expressive subjects, including landscapes, townscapes, and harbor scenes, are characterized by luminosity and transparency, rhythmic compositions of the pictorial space, black contours, and an intensive use of color. After her artistic beginnings in the circle around Mondrian, Jacoba van Heemskerck joined the center of the avant-garde movement emanating from the "Sturm" of Herwarth Walden in Berlin--the gallerist and publisher who made artists like Marc, Kandinsky, and Jawlensky famous. Her creative work resonates with environmental movements today thanks to her understanding of nature and the cosmos as an interconnected whole.