The agates of Casas Grandes and Parcelas tend to be
very similar in cut/polished appearance that they sometimes can be confused
with each other. I wasn't even sure which is Casas Grandes or Parcelas
until I finally obtained a bunch of true Casas Grandes Agates. It is common
to find Casas Grandes that is white to gray with "snow" dots in them, with
many of them being hollow, but there had been a number of agates coming
with the pink, blue, lavender, yellow, orange and purple colors. What distinguishes
the Casas Grandes Agates from Parcelas Agates is that Casas Grandes Agates
tend to look bit more "rusty" (yellowish) while Parcelas Agates tend to
come with more reddish dark skins. Those agates are one of few oldest agates
mined in Northern Mexico (1955), but ever since, there had been some sparse
mining of those agates due to the fact that they have to work on the hard
andesite bedrock to get at the agates as well as the fact that about 75%
of the nodules contain nothing but siberite (brown "calcite").
