This achievement is simple enough and if you have a previous save from the original Diablo III, you can get this within the first few minutes of booting the game up. Simply all you need to do is combine a set of gems into a new, higher-tier with the Jeweler. If you have any spare low-tier gems to combine (such as chipped Emeralds/Rubies/etc...), it makes it cheaper and easier.
If you don't have a previous Diablo III save and need to start from the beginning, the Jeweler is found during the quest 'Blood and Sand' during Act II. After finding him and escorting him out of the Aqueducts, you'll be able to use his services in town. Use any of the gems you've saved to transmute a higher-tier gem to unlock the achievement.