[foqrttjl] Pure isotope collection

Chemical element collections are nice.  Far more impressive would be pure isotope collections.

The boundary between stable versus radioactive with a very long half-life is fuzzy.  There are 253 + 33 = 286 which seem stable enough: primordial nuclides.  We limit to this list so that your nuclide collection doesn't decay away on you, though the list could be expanded much further if we include all isotopes that don't decay very much within a human lifetime.

Some, perhaps many, of these purified isotopes are very expensive, though expense doesn't seem to deter hard-core element collectors.  This video describes calcium-48 at $250000 per gram.

Among the primordial nuclides is uranium-235, half-life 700 million years.  It is likely very difficult to obtain in purified form, because atomic bombs.

Or, much more cheaply, 286 cards with facts on them.