adamant.

listen to the pronunciation of adamant.
English - English
a rock or mineral held by some to be of impenetrable hardness; a name given to the diamond and other substances of extreme hardness
a magnet; a lodestone

And I shall have no power to follow you.

any substance of exceeding hardness or impenetrability
\AD-uh-muhnt\, adjective: Not capable of being swayed by pleas, appeals, or reason; not susceptible to persuasion; unyielding
{n} a diamond very hard stone, loadstone
not capable of being swayed or diverted from a course; unsusceptible to persuasion; "he is adamant in his refusal to change his mind"; "Cynthia was inexorable; she would have none of him"- W Churchill; "an intransigent conservative opposed to every liberal tendancy"
A very tough metal which is usually utilized in the making of the sword Excalibur In 5, the Adamantium metal is the material which powers the meteors (the ones that travel between the First and Second Worlds)
hard; not giving in; unyielding; something which won't break; insistent; refusing any other opinion; surrendering to nothing
very hard native crystalline carbon valued as a gem
(Heb shamir), Ezek 3: 9 The Greek word adamas means diamond This stone is not referred to, but corundum or some kind of hard steel It is an emblem of firmness in resisting adversaries of the truth (Zech 7: 12), and of hard-heartedness against the truth (Jer 17: 1)
athamaunt
inexorable
an embodiment of impregnable hardness
{s} unyielding, firm, immovable; hard
resistant to reason; determined; inflexible; unshakeable; unyielding
It is now a rhetorical or poetical name for the embodiment of impenetrable hardness
{i} something unyielding, something immovable; something hard; stone similar to a diamond
Churchill; "an intransigent conservative opposed to every liberal tendancy
Lodestone; magnet
A stone imagined by some to be of impenetrable hardness; a name given to the diamond and other substances of extreme hardness; but in modern mineralogy it has no technical signification
If someone is adamant about something, they are determined not to change their mind about it. The prime minister is adamant that he will not resign Sue was adamant about that job in Australia. + adamantly ada·mant·ly She was adamantly opposed to her husband travelling to Brussels. determined not to change your opinion or a decision that you have made (adamas , from )
a rock or mineral imagined by some to be of impenetrable hardness; a name given to the diamond and other substances of extreme hardness