THE BLACK RING
A black ring worn on the middle finger of the right hand is often used by asexual people as a symbol of asexual pride.
Wearing a ring assosiated with the asexuality can make you feel more connected with the wider asexual community and signal to other asexual people your orientation.
There's no set of requirment for the ring, other than an overall black color. Some people opt for black rings with purple gems, simply bands of black tungsten, or decorate them with symbols of the asexual flag.
In contrast, a white ring worn on the middle finger is a symbol for the aromantic community.
(Obviously, a black ring can be worn for many reasons, so you shouldn't outright assume that if you see a stranger wearing a black ring that they are asexual without other context clues.)
This is the asexual ring that I personally wear!
The creation of the symbol of the asexual ring can be traced back to a 2005 AVEN post, in which members were discussing ways that they signal their asexuality in public through fashion or accesories.
Unfortunately, I've noticed that the knowledge of the asexual black ring has declined in recent years.
Sadly, I attribute this not to the ring falling out of fashion, but the rampant rise of aphobia and abuse that I witnessed the asexual community suffered from the hands of other lgtbq people in the late 2010s.
Fortunately aphobia is lessening within the lgbtq community, and I am hoping that this trend will make a comeback and make other asexual people feel as though they are part of a wider community.