No, that is pretty RL mythology (picked up to some extent by marvel).
Never heard that bit of lore. I've had adamant weapons in 4e and 5e and they never disintegrated in sunlight. Thanks for the info, when did that come about and when was it dropped I wonder?
Metallic sure, but black comes from its historical origins. It was also described as a metal before D&D as well (though originally associated with unprocessed diamonds which a black).
I am not saying adamantium weapons are not a D&D thing, I am just point out is origins predate D&D.
1e Fiend Folio
"Drow wear a fine mesh armour of exquisite workmanship. It is made of an alloy of steel containing
adamantite. Even the lowliest fighters have in effect +1 chainmail, with higher level drow having +2, +3, +4 or even +5 chainmail. Small bucklers are also used - shields of. unusual shape - those drow of greater experience level and importance in drow society having bucklers fashioned of
adamantite so as to be +1, +2 or even +3 value.
As will be described later, all drow move silently and with graceful speed, even when wearing their
black mesh of armour. Each drow carries a small amount of personal wealth in a soft leather bag worn around the neck beneath the mail. In addition they arm themselves with long dagger and short sword of
adamantite alloy (+1 to as high as +3 or even +4 borne by noblefolk); 50% or more carry small crossbows which are held in one hand (6" range light crossbow) and shoot darts coated with a poison which renders the victim unconscious (saves at -4)T.hes e darts also inflict 1-3 points of damage on a victim. A few drow also carry
adamantite maces (+1 to +5) and/or small javelins (also poisoned with the same substance as the darts) with atlatls (9" range, +3/+2/+1 to hit at short/medium/long range)."
So drow use an adamantite alloy that is black. Interestingly, they aren't the only creatures mentioned as using it.
"Githzerai hold a few fortresses on the Prime Material Plane but these are, particularly strong holdings, with
walls of adamantite rising as huge squat towers from dusty plains. Each houses about 500 githzerai."
"This fearsome slaad lord always appears as a skeletal, black, flightless, bat-winged man 12' tall wielding a sickle which measures 8 from tip to handle. He is always in shadow. The sickle is made of
adamantite and has the word 'death' inscribed on its blade in the slaad tongue. It has a magical bonus of +5..."
The latter two items do not disintegrate, so that aspect of drow items comes from elsewhere. I remember reading, but haven't looked it up, that the drow use underdark energies to enchant their items, which is what causes the sunlight to destroy the items.
Edit: Here it is, also from the 1e Fiend Folio
"...vast underground cities of carven stone and minerals, places of weird and fantastic beauty
inundated with unknown radiations which
impart the special properties to their items. When these are exposed to direct sunlight, irreversible decay starts and the items will become totally useless in 2-12 days. If protected from sunlight, they will retain their special properties for 31-50 days before becoming normal items;
and if exposed to the radiations of the Drow homeland for a period of 1 week out of every 4 weeks, the items could remain potent indefinitely. Drow sleep poison decays instantly in sunlight, and will lose its effectiveness after 60 days in any event after being exposed to air, although unopened packets of the poison will remain potent for up to one year."