The pendant for this necklace is a pill box locket measuring: 4.2 x 3.8 x 2.5 cm. (1 3/4" x 1 1/2" x 1"), that I made from a hand-finished tagua nut (vegetable palm ivory);  into the lid of which, I inlaid a 10 x 8 mm.  hematite cabochon.   

The swivel lid closes tightly to keep your treasures safe.  

Its inner chamber’s dimensions are approximately: 2 x 2 x 1.5 cm. (3/4" x 3/4" x 5/8").  
I  filled all cracks inside, due to germination, with tagua dust and  a non-toxic, acrylic furniture finish, that I then ground smooth.

For the neckpiece itself, I did macrame with milk chocolate brown and variegated colored hemp twine, using: hematite ovals and rounds, bone skull beads, wooden rounds and a wooden donut, and brass donuts and rondlelles.  

The length is adjustable, from 33 cm. (13"), up to 102 cm. (40").
Just slip it over your head and slide the bone lock bead to the desired length.

This necklace is made for people of all sizes to wear any length.
If you would like it shorter, you can specify the length desired at time of purchase (no less than 60 cm. or 24" so it will still fit over your head), and I can easily shorten it.

The necklace also comes with a storage pouch for safe keeping.

Tagua nuts are a renewable product of the rain forests of Central and South America. 
They are a viable alternative to animal ivory.
The last photo shows a raw tagua nut so you have a better idea what I start with.
Each nut has its own unique pattern, similar to a fingerprint.