What for?

Really good. I think the keys and veins were a little confusing, but otherwise great.

There's some really interesting stuff here.

I love connection you make here with the value of life and the value of gems and the image of blood (as life) beading like a gem. There's layered meaning in a really interesting and clever way.

Gems and lives can be said to be valuable because we decided they are.

They can be said to have value because they are able to be passed on, a wedding ring or the results of your life's work might be a legacy for a future generation.

They can be said to have value because of the stories that surround them.

What good is a life or a gem if it's spent locked in a box.

What good are lives if they only lead to polluted skies (or can only be spent looking at polluted skies).

You tell a strong story from a progression of strong images. I thoroughly enjoyed it.

I would end the poem with a period instead of a comma. The comma seems out of place and a period would give the poem a proper end. You could also just take off the comma too. I would also add a comma after "well" in the line "well which is it." The poem seems very creative, but I agree with the other commenter about the confusing keys and veins.