If you’re fascinated by jewelry closures and enjoy engineering special clasps and bails, you’ll love Cathleen McCarthy’s February 24th post on her blog, “The Jewelry Loupe.”

Van Cleef & Arpels was known for their willingness to take on difficult to “impossible” engineering challenges–like making a necklace that zipped up into a bracelet. One of these marvels was worn by Australian actress Margot Robbie at the Oscars this year. For more information, check out McCarthy’s blog.