For high-end jewellery, go to Takashimaya Shopping Centre, right
along Orchard Road. You can see branded one like Tiffany, Cartier,
Goldsmith shops are plenty, in Chinatown area, mainly in People Park
Centre and Complex (both builds are opposite each other), Chinatown
Point, etc. Alot of walking and shopping.
If you are interested in jade carving go to Smith street in
Chinatown, Singapore. More carving can be seen at our National
Museum where they exhibit some jade, quartz, serpentine carving,
rather small section. If you are buying jade, ask whether it is
natural A-jade, B-jade or C-jade. A-jade is natural without
treatment, B-jade is bleached and polymer impregnated, C-jade is dyed
jade; plus one more B+C-jade that is latest treated one with
bleached, dyed and polymer impregnated jade. Check it out.
Make sure that your tour guide are licenced because some of the
unlicence one bring tourist to shop that sell synthetic gem as
natural. Always ask around and check.