The Dazzling Band of Greed is a ring and is so named because it was crafted in a dark green metal with platinum highlights to resemble a two-headed serpent that appears to wrap delicately around the wearer's finger. The ring has an insatiable hunger for gems and, when these are not available, coins.
When first unearthed, the ring will only fit on the smallest digit of any small or medium-sized person - it is a pinky ring and should be described as such. When first worn, the ring will glow with enough light to illuminate a 10' radius, going dark when the pinky finger is held normally. Experimentation will prove that sticking one's pinky finger up and out will result in the light activating and it will not activate easily or accidentally.
If a glove is placed over the Dazzling Band, the ring will constrict tightly, pulsing in increasingly painful contractions and finally shutting off blood to the fingertip. The ring will not allow itself to be worn under a gloved or gauntleted hand for any length of time.
Once worn for several days or sleep periods, the owner will notice that the ring is now on the ring finger. The wearer will have no recollection of having moved it from the little finger. Upon noticing this, the individual wearing the ring will sense that they may attune themselves to the ring should they take the time to carefully study and consider the magic construct. If they elect not to attune with the ring, the ring will cease to provide light and, if worn under a glove, it will readily break the finger it is adorning.
Should the owner attune themselves to the ring, they will know that the ring, when placed on the ring finger, will act as a +1 ring of protection. Less obviously, whenever the owner is poisoned, the ring will sink tiny fangs into the finger of the wear and draw the poison out of the wears body, effectively neutralizing any poison or toxin. (Poison neutralization can only happen once per day.)
When worn on the middle finger, the ring can be used to cast a form of "Hypnotic Gaze" with the following rules:
As a bonus action, choose a creature that you can see within 15 feet of you. If the target can see you, it must succeed on a wisdom saving throw against the ring save DC 12 or be charmed by the ring until the end of your next turn. When charmed, the creature is unable to move, is considered incapacitated, and is visibly dazed, swaying to the movements of your hand. The effect may not be renewed. This can be done once per long rest period.
Using this ability does result in a magic light-show of sorts and marks the wielder clearly as the owner of a powerful magic item or a caster of spells. Both hostile and friendly bystanders should act accordingly.
Wearing the ring on the index finger grants water breathing and adds 10' of water movement. Water breathing is done by holding the ring under one's nose or by pursing it between one's lips. The ring will also illuminate when the index finger is pointed upwards. Keep in mind that this does not negate the other deadly effects of great depths.
Placing the ring on one's thumb will result in the leading head of the ring opening its fanged mouth - a position it will hold for several minutes and then suddenly snap shut with an audible click. Placing items into the small mouth of the ring will result in no reaction unless the object is a gemstone listed below:

    Emerald (200 gp value minimal;remove disease or poison)
    Ruby (heal 1d6 per 100 gp of value, max 5d6)
    Sapphire (500 gp value minimal; invulnerable to all damage until end of next turn)
    Diamond (200 gp value minimal;change the ring finger effect to +3 ring of protection for 6 hours)

Once a gem is 'loaded,' the effect can later be used as a bonus action which consumes the gemstone. The ring will eventually consume the gem in 1d3+1 days - it's willpower against ravenous hunger gives out and the gem will be forfeit. As the ring approaches the appointed time when it will consume the gem, the wearer will start to feel pangs of hunger that they cannot soothe.
Occasionally the ring will seize a gem from the hand of the wearer. If the wearer is unaware of this ability, it surely is a surprising way to learn. If it has not been fed for several days, it will eat the occasional coin, usually when ones’ hand is put in a pouch to grab coinage.
If you wish to change gems, the ring will consume the currently placed gem and not provide a benefit beyond a wan, loving glow. The spirit of a hydra was used in the making of this device and the gluttony of that spirit acts whenever it can.
After gaining three levels whilst wearing the band, the ring will have learned the mind of the wearer well enough to move itself from finger to finger provided the wearer uses a bonus action in order to concentrate sufficiently to spark the ring to slither from one finger to the next.