Hessonite garnet (Gomedha) cutting: distinguishing cinnamon stone from spessartine in Ratnapura?
What optical absorption lines and specific gravity tests verify Sri Lankan grossular hessonite over darker African spessartine garnets in field parcels?
More
3 Answers from travellers
Hessonite is the grossular variety of garnet (calcium-aluminum silicate), celebrated in Sri Lanka as Gomedha—the astrological gem for the lunar ascending node Rahu. Diagnostic field identification relies on microscopy and optics: Hessonite possesses a characteristic "heat-wave" or roiled internal growth texture (treacle effect) caused by transparent inclusions of rounded diopside crystals and apatite, giving it an oily appearance under 20x magnification. Its refractive index sits between 1.740 and 1.748 with a specific gravity of 3.60 to 3.68. Spessartine displays a higher RI (1.79-1.81), heavier density (4.12+), and a sharp manganese absorption spectrum band at 412nm.
Dealers prize warm honey-orange stones called "cinnamon stone"; brownish-red overtones indicate high iron content and trade at a discount.
Alluvial gravel deposits around Nivithigala and Pelmadulla yield water-worn hessonite pebbles that can be screened quickly using heavy liquid sorting.
You must be logged in to post an answer.
Log In to AnswerRelated questions
- Wildlife parks in Sri Lanka beyond Yala - Wilpattu, Minneriya, Udawalawe - which is worth visiting?2 answers
- Kandy Esala Perahera - when does it happen, where are the best viewing spots, and how do I get seats?2 answers
- Arugam Bay vs Weligama for intermediate surfing - which should I choose and why?2 answers
- Best local food to eat in Colombo - where do locals actually eat and what should I try?2 answers
- How cheap can you realistically travel Sri Lanka on a shoestring - $25-30 USD per day?2 answers
- Ayurveda retreat in Sri Lanka - what to expect and how to find genuine treatment vs tourist trap?2 answers
Join a Crew
Kandy Perahera Live Tonight
Perahera Seats, Hotels & Roads
Dalada & Perahera Culture