Begin by preparing your salt rim: pour the coarse sea salt onto a small plate, and ring it with lime juice to make it sticky. Dip the rim of each glass into the salt mixture, then set aside to dry slightly while you assemble the cocktail.
In a cocktail shaker, combine the tequila, lime juice, curaçao, activated charcoal, and simple syrup. Fill the shaker with ice and seal the lid tightly.
Shake vigorously for about 15 seconds until the mixture is well chilled and the activated charcoal is fully dispersed, giving the drink its dark, ink-like appearance.
Remove the shaker lid and place a strainer over it. Pour the dark, smoky cocktail into the prepared glasses, filling them to the desired level. Watch as the drink maintains its deep, mysterious color.
If desired, garnish with a lime wedge or a thin slice of citrus for a pop of color and aroma. Serve immediately and enjoy the striking appearance and smoky flavor.
