Ah, found it:
Before the Speaker calls each session of the House to order, the coin silver inkstand is placed on the Speaker’s lectern. The inkstand is considered the oldest surviving relic of the House, dating from between 1810 and 1820. Although its origins are mysterious, it most likely came into the House around 1819, when the old Chamber (now Statuary Hall) was first in use. The inkstand’s earliest record is an 1821 portrait of Henry Clay in the Smithsonian National Portrait Gallery, where is pictured on a table at Clay’s side. The inkstand is stamped with the mark of J. Leonard, a Georgetown silversmith and watch maker. The tray contains three crystal inkwells and is adorned on both sides by swags and medallions with eagles. The feet of the tray take the form of fasces with snakes winding around them, a classical symbol of wisdom supporting authority and the strength of unity.
The inkstand is made of coin silver (.90 purity), and has a rectangular shape, measuring 11 ¼ inches long by 7 inches wide by 2 ½ inches deep. It has a hinged handle, which stands six inches in height. Three pressed glass ink containers sit in the stand.
Thanks for the great history lesson. Had never heard it before.