Sephora Lavender Fields is a cool lavender with a sparkle finish that is discontinued and retails for $10.00. In comparison, Marc Jacobs Beauty (Luna)tic (64) is a cool lavender with a pearl finish that is permanent and retails for $26.00.
Marc Jacobs Beauty (Luna)tic (64) is 90% similar — it is more shimmery, darker, more pigmented.