1 cm big piece of pure lanthanum.
<a href="//commons.wikimedia.org/wiki/User:Jurii" title="User:Jurii">Jurii</a> (Original uploader was <a href="https://en.wikipedia.org/wiki/User:Lanthanum-138" class="extiw" title="en:User:Lanthanum-138">Lanthanum-138</a> at <a class="external text" href="https://en.wikipedia.org">en.wikipedia</a>
CC BY 3.0
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