strontium86

Strontium-86 is a stable, non-radioactive isotope of the element strontium (atomic number 38). It has 38 protons and 48 neutrons, giving it an atomic mass of 86. It is one of the four naturally occurring isotopes of strontium, the others being 84Sr, 87Sr, and 88Sr. In natural strontium, 86Sr accounts for roughly 9–10% of the isotope composition, making it the second most abundant stable isotope after 88Sr.

In nature, strontium occurs in minerals such as celestite and strontianite, and its isotopic composition is studied to understand geological and environmental processes. The ratio of 87Sr to 86Sr (87Sr/86Sr) is widely used in geochemistry, geology, and archaeology to trace rock sources, environmental changes, and provenance, because 87Sr is radiogenic, produced by decay of 87Rb, whereas 86Sr remains a stable reference. Although 87Sr/86Sr ratios are informative, 86Sr serves as a stable reference isotope in analytical measurements.

Analytical techniques such as thermal ionization mass spectrometry (TIMS) and multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) measure strontium isotopes with 86Sr frequently used for calibration, normalization, or as an internal standard during isotope ratio determinations. The stable nature of 86Sr makes it suitable for calibration standards and reference materials in isotopic studies.

Overall, strontium-86 is a stable constituent of natural strontium and plays a key role in isotopic analyses that investigate geological, environmental, and archaeological questions.