Catuṣkoṭi (Pvt) Ltd · Ratnapura & Colombo · Sri Lanka
Colour sets a gem’s price. Ceylon origin adds to it. We study colour as scientists, and we own the ground it comes from.
Illustrative · how a blue sapphire passes light across the visible spectrum
Colour
Colour is most of what a coloured gem is worth, and judging it is a craft. A good dealer reads a stone in moments: royal, cornflower, a touch of silk. Yet colour is also one of the hardest things in science to pin down. It shifts with the crystal’s orientation, its inclusions, the cut and the light. We spent careers in industries where colour had to be right every time. That discipline sharpens our eye, and it guides how we choose rough, how we cut it, and how honestly we describe every stone.
Two blues anyone might call royal. Illustrative swatches.
The trade’s colours
Pigeon’s blood and royal blue are the two most valuable colour names in ruby and sapphire. Yet no lab publishes numbers for them. Each judges by eye against its own master stones, and their definitions differ.
Ruby
Estimated from GIT’s pigeon’s blood reference stones
A vivid red with no blue or brown modifier, lit from within by red fluorescence: high chromium, low iron.
SSEF · Gübelin: untreated, strong fluorescence. GRS: heated stones can qualify. Gübelin “Crimson Red”: the same colour, with weak fluorescence.
Sapphire
Estimated from SSEF’s royal blue master set
A saturated, vivid blue, pure or with a very slight purplish tint, judged against master stones.
SSEF · Gübelin: untreated stones only. GRS: its own “GRS-type” range; conventional heating not excluded.
Same words, different rules. A heated ruby can be GRS-type “pigeon’s blood”, but never “pigeon blood red” at SSEF or Gübelin.
That’s why we study colour so closely.
Approximate colours, taken from the reference stones labs publish. Real stones glow in a way no screen can show. Sources: GIT, SSEF, Gübelin, GRS.
Source
A fine Ceylon stone, unheated, from a known pit, is worth more, and it’s harder to fake.
Where
On our own land in the Ratnapura district. Not a dealer’s packet.
How
Professional teams, and a written settlement after every sale.
Cut
Colour first, weight second.
Treatment
Heated or not, we tell you. We were there.
Certified
Lab reports for fine stones.
Work with us
01 · For mining teams
Licensed, experienced teams can work our gem-bearing land in the Ratnapura district on a revenue share agreed upfront.
02 · For dealers
Natural Ceylon sapphire, spinel, chrysoberyl and more, from our own mines, to the trade in Colombo and abroad.
03 · For industry
Where colour decides whether a batch is accepted, we set the standard and the method with you, and advise on colour and process chemistry.
About
Catuṣkoṭi is a Sri Lankan company built on two strengths: gem-bearing land in the Ratnapura district, held by our family for generations, and a deep understanding of colour.
Our land is mined professionally, by our own teams and by licensed partners. Our colour expertise comes from decades in industries where colour decides whether a product is accepted: thread, textiles and apparel.
We bring that discipline to Ceylon gems, in how we select rough, how we cut it and how we describe every stone. Measuring gem colour precisely remains our long-term research.
Leadership
Sasanka Bandara, Managing Director. A chemist by training, with a career in colour and manufacturing at Coats, MAS Brands (General Manager, Sri Lanka and Bangladesh) and Brandix. Founder of Huey, a colour-measurement venture for the tea industry.
BSc (Hons) Chemistry, University of Colombo · MBA, University of Sheffield · Executive programmes in advanced management and finance, Columbia Business School
Contact
Land, rough, colour, or a question we haven’t thought of. We reply to every message.