"his tumbler turned upside down with an unfinished bit of nibbled sugar"
Russian tea
Creative Commons Attribution Share AlikeRussian tea - Credit: Jürg Vollmer / Maiakinfo

 In Russia, tea is usually served in a glass tumbler rather than a china cup or mug. The tumbler is placed in a metal cup holder, which is often elaborately decorated. Sugar was often taken with tea by holding a piece in the mouth and sucking the tea through it to sweeten it; this habit has since died out.