Crinoid Jewellery Box

April 2007

Work In Progress

The Plan

Crinoid
fossil

Crinoid fossil

I bought a fossil. Rachel needs a jewellery box, and it's her birthday soon.
A plan!

The particular fossil is a large flat slab (6" wide) of pyritised crinoids. It's big and it's flat, so as soon as I saw it I thought of setting it in the lid of a box.
The tricky part is that I don't yet have such a box, and I've only a few weeks to get it done. Oh well.

Eventual plan is for something in dark fumed oak to complement the dark Giger-like nature of the fossil. I'll post drawings as I think of ideas.


First sketch of a lid design

First sketch of a lid design

First ideas

I was planning on just a simple framed panel construction. Four wide rails tenoned together and there's a non-straight groove down the middle to hold the fossil. The rails will probably have a "bridge" section (hump down the middle) to try and imply squareness to the overall lid, whilst the inner width is form-fitting around the fossil.

There's also the question of conservation. Do I make something that's nice cabinetry, or that's a nice display cabinet. Should I do dust and humidity control by putting it under glass? -- hence my sudden interest in the conservation stability of pyritised fossils.

More to come!


An old engraving of Cretaceous Apiocrinites rotundus crinoids

Cretaceous Apiocrinites rotundus crinoids

The Fossil

It's a Crinoid or "sea lily", Pentacrinites fossilis. Although they resemble branching seaweeds, the crinoids are animals with five-fold symmetry like starfish and sea urchins (their very distant relatives).

Like most of the good pyritised crinoids, this one is from the well-known Bed 84b at Black Ven near Charmouth and Lyme Regis, on the South West coat of England. From the Lower Jurassic period (180 - 190 million years ago).

There's some debate as to whether crinoids lived attached to the sea bed, but the recent view of Pentacrinites is that they floated around attached to driftwood. When the log became waterlogged, it sank and took them to the bottom.

I bought this example from Crystal Planet, after seeing it at a Rock & Gem show locally, then agonising over whether to buy it for a few days. I couldn't afford it, I couldn't find a customer wealthy enough to buy a box using it, so the only solution was to give it away! As soon as I'd seen it, I knew it would be perfect for insetting into some piece of cabinetry. Yes, it was expensive. You can find them for much less, but not in this size.

There are also bigger pictures of the top and bottom.
Thanks to Pentti for the fossil photos.


Crinoid Links