Final answer:
Santiago receives two stones named Urim and Thummim from Melchizedek, which are meant to help him interpret omens in 'The Alchemist'.
Step-by-step explanation:
The names of the stones that Santiago receives from Melchizedek in The Alchemist are Urim and Thummim. These stones are given to Santiago to help him interpret omens. It is important to note, however, that the provided reference texts do not directly relate to the question asked about Santiago and Melchizedek from The Alchemist. Instead, those references appear to discuss various historical and cultural aspects of different types of stones and their significance in various contexts.