You say this small albedo is most probably closely connected to high temperatures. "1100 degrees Celsius hot enough to melt gold" is a large underestimation. It is hot enough to melt some rocks and most metals! And together with high sun radiation and magnetic fields it is hot enough to form plasma.
Plasma is a key here - it can both be a perfect mirror or a perfect absorber depending on condition and frequency of electromagnetic radiation. For example our Sun, having "plasma envelope" is also an "almost black body".
And being a black body doesn't mean "pitch black". It's quite the reverse: it means - shine brightly (at least at some specter - IR, visible, X-ray, so on.) with our Sun being good example.
So if we put that "Dark Knight" planet away from its star it would rise its albedo dramatically.
To have such a low albedo without plasma is impossible - there is just no such material. But using some special "metamaterials" we can create the illusion of super low albedo. The metamaterials I have in mind are small glass balls (which are closely connected to cooling down plasma). They act as perfect retroreflectors - all light which is coming to that planet is reflected to its source. So sand made from these glass balls would look black if looked at from the side, but would shine brightly if we looked from the light source.
Btw, we already have such situation before our own eyes: the Moon. Its surface shines brightly when the Moon is full. But its albedo drops greatly (lower than black earth) when it's a half moon.
The only thing that can spoil everything - is atmosphere. For our Earth atmosphere plays a great role in its albedo.
So, to summarize, you need the following to create "The Cold Dark Knight":
- No atmosphere at all
- Planet is made mostly of silicates (to form glass)
- Planet is covered with a sand/gravel mix made from small (0.1 - 10 mm) nearly perfect glass balls
This can be achived if the planet quite recently got away from being close from a star:
- All its "normal" atmosphere was blown away with solar winds
- Cooling plasma would form that "glass ball" sand (it's actually one of the technological processes to form fine glass balls for retroreflectors)
- Asteroids and tectonics would not destroy that glass-field yet.
Btw, for the last - asteroid craters would form very bright circles on that black surface.
And do not look at that planet from starside: you may blind your eyes and devices.
alternate Earth
for the sake of your question? Aside from composition, what about mass or radius? Does it need to have a water cycle and Earth-like temperatures? $\endgroup$