Complex sentence: Italian witches during the Roman period believed that small pieces of serpentine stone could protect people from venomous creatures such as snakes or spiders, as the dark green and streaked with white color resembles the appearance of the snakeskin.
Split into simpler sentences: Italian witches during the Roman period believed that small pieces of serpentine stone could protect people from venomous creatures such as snakes or spiders. The reason is that the dark green color streaked with white color resembles the appearance of the snakeskin.