Maya blue, so dramatic a preparation. That like the frothing madder preparation shown in Yoshiko and Michel's DVD and workshop had us all wowing.
There are, in fact two relatively local sources of sepiolite, one in Florida and the other in Nevada.
It is also known as salt clay or sea mud (it isn't a deep sea ooze), it is a clay.. a silicate (hence the warnings on the MSDS sheet), though not a fibre and it hydrates in sea water... which makes it great for using in the off shore rigs rather than bentonite that is the usual drilling mud.
Thanks to Mat for sharing his knowledge.
So my initial fears about it closing up my lungs may have been exaggerated.... I will continue to investigate.
Go here for geochem of sepiolite
3 hours ago