This ingredient is optional but it looks so pretty in the rum Halloween cocktail! Offering a shimmery, pearlescent look, edible pearl dust, also known as luster dust, comes in various colours and can be used to decorate drinks or brush over food. Added to this sour grape schnapps and strawberry rum, it turns an otherwise simple drink into a mystical looking potion! Make sure you're using clear martini glasses, so the shimmer is clearly visible. Ingredients vary by brand but iron oxide, titanium dioxide, mica, and carmine feature in some. In small amounts these ingredients are perfectly safe.