Is strontianite radioactive?
Is strontianite radioactive? No: the mineral is SrCO3, with no uranium. Of 45 carbonate species sheets, only 7 uranyl ones print radioactive; calcite does not.
No. Strontianite is strontium carbonate, Sr(CO3), 59.35% strontium, with no uranium, thorium or potassium, and its Handbook sheet prints no radioactivity. Of 45 carbonate sheets checked here, only the 7 uranyl carbonates print Radioactive. Natural strontium is stable; strontium-90 is man-made by nuclear fission (US EPA). This is not safety advice.
In short
- The formula and the sheet. The September 2026 IMA-CNMNC Master List writes strontianite as Sr(CO3), status G, 1791, United Kingdom. A script finds strontium, carbon and oxygen and no uranium, thorium or potassium. The Handbook of Mineralogy sheet has no radioactivity line; it says fluorescent under UV, which is light, not radiation. Its one analysis, from Strontian, Scotland, reports CO2, CaO, SrO and BaO, total 99.53.
- The uranyl rule. A script read every Handbook sheet cached here whose header formula contains CO3: 45 sheets. Seven print Radioactive: rutherfordine, zellerite, liebigite, andersonite, swartzite, bayleyite and schröckingerite, and every one has UO2 in its formula, from 26.79% to 72.12% uranium by mass, worked. The other 38 print no radioactivity, and none has uranium or thorium in its formula.
- Strontium carbonates in the ledger. Four of the 45 hold strontium in the formula: strontianite, ancylite-(Ce), burbankite and carbocernaite. None prints radioactivity. On the IMA list, 22 parsed carbonate rows contain strontium and none contains uranium or thorium.
- Documented limit: silence is not zero. The ancylite-(Ce) sheet prints ThO2 0.20 and 0.53 in two analyses, 0.18% and 0.47% thorium, and still no radioactivity line; one of the two is from the Khibiny massif, a place also named on the strontianite sheet. Strontianite’s analysis did not report thorium or uranium at all, so this page states the formula and the wording, not a measurement.
- What about strontium-90? The US EPA, Radionuclide Basics: Strontium-90 page says naturally occurring strontium is not radioactive and that strontium-90 is produced through nuclear fission; ATSDR gives its half-life as 29 years. The stable-isotope arithmetic is on is celestite radioactive and is not repeated. The general method is on is my mineral radioactive; this is not health, safety or legal advice.
| Sheet | Formula (sheet header) | U or Th in the formula? | Prints radioactive? | U or Th by mass, worked | Strontium in the formula? |
|---|---|---|---|---|---|
| Strontianite | SrCO3 | No | No | Not reported in its analysis | Yes, 59.35% |
| Ancylite-(Ce) | Sr(Ce,La)(CO3)2(OH)·H2O | No | No | Th 0.18% and 0.47% (ThO2 0.20, 0.53 printed) | Yes |
| Burbankite | (Na,Ca)3(Sr,Ba,Ce)3(CO3)5 | No | No | No U or Th oxide printed | Yes |
| Carbocernaite | (Ca,Na)(Sr,Ce,Ba)(CO3)2 | No | No | No U or Th oxide printed | Yes |
| Rutherfordine | U6+O2(CO3) | Yes, U | Yes | U 72.12% | No |
| Zellerite | Ca(UO2)(CO3)2·5H2O | Yes, U | Yes | U 45.76% | No |
| Liebigite | Ca2(UO2)(CO3)3·11H2O | Yes, U | Yes | U 32.68% | No |
| Andersonite, swartzite, bayleyite, schröckingerite | Uranyl carbonates (Na, Ca, Mg) | Yes, U | Yes | U 36.95%, 32.58%, 28.92%, 26.79% | No |
| All 45 sheets | — | 7 yes; 38 no | 7 yes, the same 7; 38 no | — | 4 yes |
Is strontianite radioactive? What the formula and the sheet say
No radioactive element is in its formula. The September 2026 IMA list gives strontianite as Sr(CO3), status G, 1791, United Kingdom; the Handbook of Mineralogy strontianite sheet writes SrCO3 and places it in the aragonite group, with aragonite and witherite. Worked on standard atomic weights it is 59.35% strontium, the figure on the strontianite species page. A script reading the element symbols finds no uranium, thorium or potassium.
The sheet is silent, and silence is checked. A search of the sheet for radioact finds nothing, while the same search on the uraninite and autunite sheets, the positive controls, finds it on each. The sheet’s luminescence line says strontianite may be thermoluminescent, is fluorescent under UV and cathodoluminescent under X-rays and electron beams. Those are emissions of light, explained on fluorescent minerals explained, not radioactivity.
What the analysis covers. The Strontian, Scotland analysis reads CO2 30.35, CaO 2.70, SrO 66.31 and BaO 0.17, total 99.53. It did not look for uranium or thorium, and an analysis that does not report an element is not a measurement of zero. A 20.00 g piece reads 14.68 g in water at density 3.76, as on the species page.
Which carbonates are radioactive? The uranyl rule
Method. Every Handbook sheet cached for this site was read with pdftotext -layout, and the 45 whose header formula contains CO3 were kept. Thirty-five were already cached; ten were fetched on 14 November 2026, seven uranyl carbonates as positive controls and three strontium carbonates. A script then checked each sheet for the string radioact and each formula for uranium and thorium.
Result. Seven sheets print Radioactive: rutherfordine, zellerite, liebigite, andersonite, swartzite, bayleyite and schröckingerite. All seven carry the uranyl group, UO2, in the formula; worked from those formulas, uranium runs from 26.79% of schröckingerite to 72.12% of rutherfordine. The other 38, from calcite and dolomite to the lead and copper carbonates, print no radioactivity and have no uranium or thorium in the formula. On these sheets, radioactivity tracks uranium in the formula, not the carbonate.
The same check on the IMA list. Of 5,797 rows the parser reads, 377 have CO3 in the formula. Forty-one of those contain uranium and three thorium. Twenty-two contain strontium, strontianite among them, and none of the 22 contains uranium or thorium. The parser misses some rows whose formulas carry spaces, so the counts are of parsed rows, not of the whole list.
Where the rule stops: ancylite and the Khibiny analysis
Documented limit. The ancylite-(Ce) sheet, a strontium rare-earth carbonate, prints ThO2 in two analyses: 0.20 at Narssârssuk, Greenland, and 0.53 in the Khibiny massif, Kola Peninsula, where its formula carries Th0.01. Worked, that is 0.18% and 0.47% thorium by mass. The sheet prints no radioactivity line. So a sheet’s silence means the sheet says nothing, not that the material contains nothing.
Why it matters here. The strontianite sheet names the Khibiny and Lovozero massifs and three Kola carbonatites in its Distribution field, and says strontianite is “common in carbonatites”. No source fetched for this page measures thorium or uranium in strontianite from any of them, so this page gives no figure for a specimen and does not carry the ancylite analysis across. The burbankite and carbocernaite sheets print no thorium or uranium oxide at all.
What would answer it for one specimen. A measurement, which this page does not offer. The general approach for a collection is on is my mineral radioactive and how to store radioactive mineral specimens; neither is quoted here. Questions about a particular specimen, a workplace or a person go to HSE or a radiation protection adviser. This is not health, safety or legal advice.
Is strontium radioactive? Stable strontium and strontium-90
Natural strontium is not. The US EPA strontium-90 page says “Naturally occurring strontium is not radioactive”, and that the most common man-made radioactive form, strontium-90, is produced commercially through nuclear fission and is found in the environment from nuclear testing in the 1950s and 1960s and in reactor waste. ATSDR says strontium in the environment exists in four stable isotopes, 84Sr, 86Sr, 87Sr and 88Sr, and that 90Sr is formed in nuclear reactors or during the explosion of nuclear weapons, with a half-life of 29 years.
What that means for strontianite. Its strontium is natural strontium. How 9.54 g of strontium in a 20.00 g celestine splits across the four stable isotopes is worked on is celestite radioactive; the same split applies to strontianite’s 11.87 g in 20.00 g and is not repeated as this page’s check. The radium question belongs to baryte and is on is baryte radioactive; this page does not transfer it.
Where it is found and what it is used for. The sheet calls strontianite an uncommon low-temperature hydrothermal mineral in veins in limestone, marl and chalk, and common in carbonatites, from Strontian, Argyll, to Germany, Austria, North America and Kola. The USGS Mineral Commodity Summaries 2026, strontium names celestite, not strontianite, as the strontium mineral consumed in the United States. More guides are in the collecting guides. We hold no catalogue and nothing here is offered for sale; the wanted list is the only commercial route.