GemStore team — written by the people who list and pack every stone.
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What a ratti is
A ratti is the old South Asian unit for weighing small precious things. It takes its name from the seed of the ratti plant, which was once used as a counterweight on a jeweller's scale. Gemstone dealers in Pakistan still describe weight in ratti, and many buyers think of a stone as "a 5 ratti Neelam" rather than in carats.
The international unit is the carat. One carat is exactly 0.2 grams, and every certificate and lab report gives weight in carats. The converter above links the two systems.
Standard ratti and sunari ratti
Two different units are both called ratti, and mixing them up is the most common cause of confusion in the bazaar.
- Standard ratti (gem ratti): 0.91 carat, about 0.182 g. This is the ratti used for gemstones in Pakistan, and the one GemStore means whenever we say ratti.
- Sunari ratti (goldsmith's ratti): about 0.1215 g, roughly 0.61 carat. It belongs to the tola-masha-ratti system used for gold: 8 ratti make a masha and 12 masha make a tola, so a tola is 96 sunari ratti, about 11.66 g.
The sunari ratti is about a third lighter than the standard one. A stone described as "9 ratti" by a goldsmith using sunari ratti weighs about 1.09 g, which is only about 6 standard ratti. Before comparing two quotes, ask which ratti each seller is using. Some sellers use other local values, so if a weight looks odd, ask for it in carats.
Why Pakistani jewellers quote in ratti
Ratti is the unit most families grew up with. Gold has long been weighed in tola, masha and ratti, and gemstones followed the same habit. Astrologers who recommend a Pukhraj or Neelam often give the weight in ratti too, so buyers arrive asking for a stone "of at least 5 ratti" or "between 7 and 8 ratti". The trade also prices many stones per ratti, which is why it helps to know how a per-ratti rate compares with a per-carat one.
How to convert by hand
Three numbers do all the work: 1 standard ratti = 0.91 carat, 1 standard ratti = 0.182 g, and 1 carat = 0.2 g.
- Ratti to carats: multiply by 0.91.
- Carats to ratti: divide by 0.91.
- Ratti to grams: multiply by 0.182.
- Carats to grams: multiply by 0.2.
- Grams to ratti: divide by 0.182.
Worked examples
- 6 ratti to carats and grams. 6 x 0.91 = 5.46 carats. 5.46 x 0.2 = 1.092 g, the same answer as 6 x 0.182.
- A certificate says 3.64 carats. 3.64 / 0.91 = 4, so the stone is exactly 4 ratti.
- An odd weight: 2.75 carats. 2.75 / 0.91 = 3.02 ratti. Most sellers would call this "just over 3 ratti".
- Grams to ratti: 1.5 g. 1.5 / 0.182 = 8.24 ratti. As a check, 1.5 / 0.2 = 7.5 carats, and 7.5 / 0.91 = 8.24 ratti.
- Sunari ratti to standard ratti: 9 sunari ratti. 9 x 0.1215 = 1.0935 g, which is 5.47 carats (1.0935 / 0.2). Divide by 0.91 and you get about 6.01 standard ratti.
Round only at the end. Rounding 0.91 to 0.9 seems harmless, but on a 10 ratti stone it shifts the answer by a tenth of a carat.
Per-ratti and per-carat prices
Because a standard ratti is 0.91 carat, the two rates are linked by the same number:
- Per-ratti rate = per-carat rate x 0.91.
- Per-carat rate = per-ratti rate / 0.91.
The per-ratti figure is always a little lower than the per-carat figure for the same stone, because a ratti is a little less than a carat. The total price does not change: a 4.55 carat stone is 5 ratti, so its per-carat rate times 4.55 and its per-ratti rate times 5 give the same total. If two quotes for similar stones do not agree once converted, check the unit first. A per-ratti rate based on sunari ratti works out at about 0.61 of the per-carat rate rather than 0.91, so the stone can look cheaper than it is.
Weight is only one part of value. Colour, clarity, cut, origin and treatment move the price far more than a fraction of a ratti. Our gemstone prices in Pakistan guide shows per-carat and per-ratti levels across GemStore's own listings, refreshed monthly, and every stone in the blue sapphire, yellow sapphire and ruby categories shows its carat weight and its own price. If a weight on a certificate puzzles you, our guide to reading a lab certificate explains each line.
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