Urban Decay Solstice is a warm duochrome with a glitter finish that is permanent and retails for $22.00. In comparison, Natasha Denona Calypso Blue (05M) is a warm duochrome with a sparkle finish that is permanent in palette and retails for $29.00.
Natasha Denona Calypso Blue (05M) is 90% similar — it is more shimmery, darker, more pigmented.