Google Does Not Give Special Treatment to Content in a Blockquote
Google’s John Mueller recently addressed the use of the blockquote element, saying it’s not treated in any special way. Mueller responded to a thread on Reddit from a user asking if putting content in a blockquote would prevent it from being seen as duplicate. In short, the answer is no. Google will crawl the content just as it would anything else. When Google sees a blockquote it will not disregard the content while assuming it’s from another source.