<?xml version="1.0" encoding="utf-8"?><mads xmlns="http://www.loc.gov/mads/" xmlns:mods="http://www.loc.gov/mods/v3" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.loc.gov/mads/
mads.xsd"><authority><topic authority="http://AATesaurus.cultura.gencat.cat/aat/getty_en">Potsdam sandstone</topic></authority><related type="broader"><topic>siliceous sandstone</topic></related><variant type="other"><topic>sandstone, Potsdam</topic></variant> <note xml:lang="en"><![CDATA[ A siliceous sandstone, from Saint Lawrence County in New York, containing a small amount of iron oxide, giving it its red or reddish-brown color. Although soft enough to work economically when first quarried, it becomes incredibly hard upon exposure, making it an incredibly durable building stone. ]]></note></mads>