OneCeylon
All questions

Short-wave UV fluorescence in synthetic vs natural Ceylon ruby: chromium emission spectroscopy?

Seen by 1,310 travellers
Jump to the accepted answer
E
Elena Lumens•910 rep

How do gemmologists utilize 254nm short-wave ultraviolet fluorescence to distinguish flame-fusion synthetic rubies from untreated natural Ratnapura stones?

27

5 Answers from travellers

✓Accepted Answer

Diagnostic fluorescence testing of red corundum requires inspecting emission reactions under filtered 254nm Short-Wave Ultraviolet (SWUV) radiation. Flame-fusion (Verneuil) synthetic rubies are manufactured from pure alumina without natural iron impurities; lacking iron quenchers, they fluoresce with intense, saturated crimson-red luminescence under both SWUV and LWUV. Natural Ceylon rubies contain trace iron (Fe3+) substitutions that partially quench fluorescence, resulting in a moderate to dull orange-red glow under LWUV and an inert or chalky purplish-blue response under SWUV. Under immersion, synthetics also show curved growth striations.

39
D
Dr Kularatne Lab•1950 rep

Always use protective UV-absorbing safety goggles; unshielded 254nm short-wave radiation causes rapid corneal burns and photochemical keratitis.

22
E
Elena Lumens•910 rep

Hydrothermal synthetic rubies can show muted fluorescence similar to natural stones, requiring FTIR spectroscopy to identify diagnostic seed plates and heavy-water absorption peaks.

18
L
Lucas Rock•915 rep

Natural untreated Ratnapura rubies characteristically display boehmite needles intersecting at 86 degrees alongside intact, un-melted zircon crystals.

15
C
Clara Gastronomy•885 rep

Confirm results with a desk spectroscope to verify the natural chromium doublet absorption line at 694nm in the deep red spectrum.

12
M
Max Rigging•925 rep

You must be logged in to post an answer.

Log In to Answer

Related questions

Browse all questions