Listings for square-cut blue topaz earrings commonly show darker London Blue, lighter Sky Blue, and standard Blue Topaz tones.
Product listings identify the topaz as natural in origin and note common treatments such as heat treatment and irradiation.
Closures in the listings include post/post-back for studs, leverback for some drop styles, French wire/earwire on certain dangles, and at least one listing with a clasp-style closure.
Some listings show roughly 6 mm square stones; total stone weights in the sample range from about 2.20 to 5.00 carats. Product details do not consistently map a single stone size to a specific total carat weight.
Drop lengths in these listings typically range from about 1 inch to about 1 1/4 inches.
Stud-style square topaz earrings typically list post/post-back closures, while drop or dangle styles commonly use leverback or French-wire/earwire closures.