The age is revealed by the isotopic ratio of strontium which changes with time.
From the sciencedaily.com
Once they're aligned, in the case of strontium, they stay that way for minutes.
From the sciencedaily.com
Strontium gets incorporated in tooth and bone because it substitutes for Calcium.
From the scienceblogs.com
But until now it has proved impossible to create a useful strontium atomic clock.
From the newscientist.com
Its reserves of strontium rank first in East Asia and the South East Asia region.
From the en.wikipedia.org
It was found that 12% of the caesium entered the plant, and 20% of the strontium.
From the en.wikipedia.org
The water contained low levels of cesium-137, strontium-90, uranium and plutonium.
From the timesunion.com
This was the crucial step that was not possible with the other strontium isotopes.
From the sciencedaily.com
Strontium 90, a known carcinogen, is a fission byproduct of uranium and plutonium.
From the lohud.com
More examples
A soft silver-white or yellowish metallic element of the alkali metal group; turns yellow in air; occurs in celestite and strontianite
A metallic chemical element (symbol Sr) with an atomic number of 38
A silvery, soft metal that rapidly turns yellow in air. Sr-90 is one of the radioactive fission materials created within a nuclear reactor during its operation. Stronium-90 emits beta particles during radioactive decay.
A metal often used in a radioactive form for imaging tests or as a treatment for cancer.
Metallic element with atomic weight 87.62 and atomic number 39. It is very reactive and so always found in compounds with other elements. One radioactive isotope, strontium 90, is produced by nuclear fission of uranium. ...
This trace element is necessary for corals, clams, and other creatures with calcareous skeletons to grow. It is most commonly added as strontium chloride SrCl2.
Symbol:"Sr" Atomic Number:"38" Atomic Mass: 87.62amu. This element is a member of the alkaline metals family. Strontium is grouped with other barium-like minerals. It is reactive and oxidizes quickly, becoming a yellowish color. You may find it in magnets, TV tubes, and nuclear reactors. ...
A trace element in natural saltwater that aids in calcerous algae growth. Also see the Saltwater Aquarium Supplements article.
No MCL has been set, but the element is analyzed using nitrous oxide -acetylene flame. The primary concern is the presence of a radioactive form, known as Strontium-90.