Moonstone
Moonstone is the gem variety of the feldspar mineral adularia (a form of orthoclase, KAlSi3O8), prized for adularescence, an internal billowing blue-to-white sheen caused by light scattering off microscopic intergrown layers of orthoclase and albite feldspar. It is cut almost exclusively as a cabochon (a smooth domed shape, not faceted) to display this optical effect across the surface of the stone. It is used in jewellery, principally rings, pendants and earrings, as both a centre stone and an accent stone, and is one of the traditional birthstones associated with the month of June.
Listed moonstone markets
Each line is a grade at a delivery point. Open one for its full specification and terms.
Grades
A sample is examined for species and variety identification (refractive index, specific gravity and optic character distinguishing feldspar moonstone from imitations such as synthetic spinel or milky quartz), then assessed on the strength, colour and coverage of its adularescence, its body transparency, the presence of visible fractures or internal stress inclusions, the precision of its cabochon cut and dome, and its weight in carats.
Gemological identification (refractive index and specific gravity)
1 grade
| Grade | Definition |
|---|---|
| RIRefractive index range | approximately 1.518 to 1.526 |
Quality-factor assessment
1 grade
| Grade | Definition |
|---|---|
| NANo fixed ladder | Reported descriptively per stone; no industry-wide numbered or lettered grade scale exists |
Grades and quality descriptions outside this list trade on request.
Locations
| Country | Region | We trade it as |
|---|---|---|
| Sri Lanka | Galle and Ratnapura districts, Southern and Sabaragamuwa Provinces | Origin |
| India | Southern India (various) | Origin |
| Madagascar | Various | Origin |
| United States | National | Destination |
| Spain | National | Destination |
| Thailand | Bangkok cutting and treatment trade | Origin and destination |
Locations outside this list trade on request.
Timing
Moonstone is mined year-round from small shaft pits rather than on a seasonal harvest calendar; the operative timing constraint is cutting and polishing lead time and export documentation, not a harvest window.
HarvestArrival
| Origin | J | F | M | A | M | J | J | A | S | O | N | D | Window |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sri Lanka | Year-round shaft-pit mining; no seasonal harvest pattern |
Timing outside this pattern trades on request.
Common questions
What grades of moonstone does SIP Global trade?
We quote 2 published grades of moonstone, including RI - Refractive index range and NA - No fixed ladder. Every grade is tied to a delivery point and a settlement route. Grades outside the published list are priced on request.
How is moonstone graded?
A sample is examined for species and variety identification (refractive index, specific gravity and optic character distinguishing feldspar moonstone from imitations such as synthetic spinel or milky quartz), then assessed on the strength, colour and coverage of its adularescence, its body transparency, the presence of visible fractures or internal stress inclusions, the precision of its cabochon cut and dome, and its weight in carats. Grading runs on 2 systems: Gemological identification (refractive index and specific gravity) and Quality-factor assessment.
Where does SIP Global trade moonstone?
We trade moonstone in Sri Lanka, India, Madagascar, United States, Spain and Thailand. Origins and destinations outside this list trade on request. We are not limited to the locations shown.
How do I get a price for moonstone?
Send the grade, the origin and the delivery window to the SIP Global desk. That is enough for a trader to come back with a level and a settlement route. 1 listed moonstone market is published on this page, each with its full specification and terms. We take both sides, physical and financial, prompt to long dated.
Standards and data sources
The grading language on this sheet follows published standards. Trade volumes and tariff lines are public record. Verify anything here against the source.
- GIAGemological Institute of America grading
- UN ComtradeOfficial international trade statistics by HS code
- ITC Trade MapBilateral trade flows and tariff data
- FAOSTATFAO production and trade series for agricultural commodities
Price this with our desk
Grade, origin and window if you have them. If what you are carrying does not fit the sheet above, describe it in your own words and a trader will take it from there.