Although there are few references to Melchizedek in pop culture, there is one book that alludes to this figure from the Bible, which is "The Alchemist" by Paulo Coelho. This book is a work of fiction in which the main protagonist, named Santiago, meets an old man named Melchizedek who states that he is the King of Salem.
This mysterious man teaches Santiago certain truths and gives him two magical stones called Urim and Thummim. Melchizedek also blesses Santiago. Melchizedek basically helps the boy begin his journey and teaches him to follow his heart and dreams. The character Melchizedek speaks about how he will not see Santiago again, just like he met Abraham once and never saw him again.
Melchizedek is a very mysterious biblical figure that is mentioned in the Book of Genesis of the Old Testament. He was a priest of God and the King of Salem who gave bread and wine to Abraham and his men after they defeated an enemy. Abraham gave Melchizedek one-tenth of the spoils he took from the vanquished enemy. Melchizedek blessed Abraham and disappeared.
Melchizedek is again mentioned in Psalm 110 and in the Book of Hebrews of the New Testament. In a passage from Hebrews, it says that Melchizedek was not born from a mother or father, alluding to his supernatural origin. There also is an allusion that suggests that Melchizedek is like Christ because he remains a priest forever.
In the book "The Alchemist", there are names given to the two magical stones. In the Old Testament, these stones are also mentioned as being part of a priest's breastplate and were used as divining tools before momentous occasions.