What is the author's style in The Moonstone by Wilkie Collins?

The structure of the novel is rather complicated. It is divided into Periods and Narratives, some of which contain chapters. Basically, each person has been asked to tell his part of the story of the missing Diamond and what happened. Some write their stories from their journals and diaries. Some of the Narratives are from letters written by the characters. All of these pieces fit together to tell the story of the novel.