- Recorded Session from May 1, 2020
- Level: BASIC to INTERMEDIATE
- Length: 1h 44m
- Upon purchase you will automatically receive the Digital Booklet “ID of Green Gems”
This webinar presents properties of the most common natural and synthetic green gems using three portable in-expensive instruments:
1. PL-Inspector/Jewellery Inspector – a mini UV lamp with magnifier to observe LW and SW fluorescence/ phosphorescence. Weak-medium chalky blue fluorescence under LWUV is a good indication of polymer impregnated (B) Jadeite jade and medium chalky yellowish green under LWUV is good sign of dyed (C) Jadeite Jade.
2. Portable polariscope – Cross polarised filters (CPF). Some green gems have strong ADR (Anomalous Double Refraction) that would indicate Glass or Synthetic Spinel.
3. Spectroscope – Use of a handheld spectroscope requires some
practice but is very useful especially on mounted or larger green gems that cannot be tested with other gemmological techniques.
Outline of webinar (1h lecture):
CPF (Cross Polarized Filters) and Spectroscope as indispensable and fast optical methods in addition to essential tools such as Loupe
Treated green gems – screening for natural colour or treatments of diamond, emerald, jade, turquoise and chalcedony based on UV reaction.
Synthetic vs Natural Green Gems – manmade glasses, CZ, YAG, synthetic spinel and emeralds also have characteristic fluorescence under LW/SW light and CPF pattern.
“PL Inspector” – portable, low-cost instrument allowing viewing of fluorescence and phosphorescence with a magnifier and app to capture and compare LW/SW reactions
Advanced techniques – Gemologists may not be able to distinguish certain synthetic and treated green gem materials with standard and portable advanced instruments, like green Diamonds, polymer treated Jade and Turquoise, some synthetic Emeralds and synthetic Quartz.
PRACTICAL WORKSHOP (30min): use of 10 green gems and diamonds under “PL Inspector” and “Jewellery Inspector” – portable, low-cost instrument allowing viewing of fluorescence and phosphorescence with a magnifier and app to capture and compare LW/SW reaction.
Use of EXA/J-screen to detect oils in emeralds.
QUESTIONS and ANSWERS (15min)