The intricate obsidian and emerald key with swirling ornate pattern appears little more than a jailer's device. It is somewhat oversized and is attached to a fine 20 inch silver chain of remarkable craftsmanship studded with aquamarines. 

Curse. Upon taking possession of the key, Granlekh seeks to attune to you. You must make a Wisdom saving throw, DC 15, or he binds to you joining his will to yours. On a success, you are able to hold the key without being bound to it for 24 hours. If you make contact with the key again, after that time, then the saving throw is repeated. Upon a failed saving throw, his nature joins to yours. The earth spirit bound to the key is full of stoic, unwavering, and cold. A resolute nature takes hold over you.

Your physical weight increases by half making swimming more difficult. The increased density of your skin increases your AC by 1 but your swim speed is reduced by half as you must spend more energy staying afloat. Your connection to earth grows and you gain the ability to cast Stone Shape once per long rest without spending a spell slot. Due to Granlekh's stalwart nature, your Constitution increases by 1. 

To end the attunement, you must feed the key an aquamarine or diamond worth 100 gp and give the key to someone else. Alternatively, you can feed the key 200 gp of aquamarines and diamonds which leaves her satiated long enough to leave her asleep in a warm, dark, place such as a box or coffer ending the attunement. Once the attunement is ended, any affects she has had on you are also lost.