which metal retains heat the longest

[Shotfun]

hi everyone. i have a question in regards to a product im prototyping. i need a solid durable material that will heat up fast and retain heat at the same temperature for 1 minute. does anyone have any good ideas? thanks for your time

[Bender]

You have two conflicting requirements: materials which heat up fast also cool down fast. Speed of heating depends greatly on the method of heating.

You will also need to quantify: "solid", "durable", "fast" and "the same".

Accumulator heating uses stone, which could qualify for all your requirements, depending on the details.