After great pain, a formal feeling comes –
The Nerves sit ceremonious, like Tombs –
The stiff Heart questions ‘was it He, that bore,'
And ‘Yesterday, or Centuries before'?
The Feet, mechanical, go round –
A Wooden way
Of Ground, or Air, or Ought –
Regardless grown,
A Quartz contentment, like a stone –
This is the Hour of Lead –
Remembered, if outlived,
As Freezing persons, recollect the Snow –
Quartz is a metamorphic rock, which undergoes a huge change that cannot be reversed. The speaker feels like a stone, lifeless and dead inside, yet she’s accepting of it. She was changed by the great pain she felt but feeling nothing is better than  feeling that pain. 
 “Quartz contentment” combines abstract and concrete.  It suggests a— paradoxically— feelingless kind of contentment— a numbness encapsulated in the  simile  of a stone.
After great pain a formal feeling comes J341 F372