Interestingly, Franklin Blake's character is not completely elucidated in The Moonstone and is, in fact, called into question on several occasions. Franklin serves as the presence behind The Moonstone, and it is he who has asked all of the narrators for their contributions and who organizes them as editor. Yet his own character remains unspecific. Often when narrators speak of Franklin, their opinions reveal more about themselves than about him. Franklin's own narrative is conspicuously bare of personal history or opinion. We can say that he is cultured and educated, capable of imaginative belief, and generally good-natured. Franklin is thought of well by many trusted characters, such as Betteredge, Mr. Bruff, and Lady Verinder. Rachel loves and trusts him, and he loves her in return. His character is called into question in his interactions with Rosanna Spearman, in which Franklin seems somewhat callous, even to the girl's memory. Additionally, he is known to be often in debt—a state only alleviated when he inherits his father's fortune toward the end of the novel. Franklin's physical appearance is un-ideal—he is short with dark facial hair.

Franklin's main conflict is in internal one similar to Rachel's. He must reconcile the objective fact of the evidence, which points to him as the thief, with his subjective opinion and memory that he did not steal the diamond. As Rachel's tragic, outcast counterpart is Rosanna, Franklin finds his tragic counterpart in Ezra Jennings.