"Treasure" Transformed

One of my favorite rocks from the past month was a striking red stone I picked up on a beach near Port Townsend.  I liked it so much, in fact, I posted it on this blog on March 12 (see below), a handsome "jasper" with a graceful white stripe running through it.

Well, after a week in the tumbler, the rock was transformed: the red is gone, and the white squiggle virtually erased. Without doing serious tests, I'm guessing this is not jasper after all, but something much softer - and that the stripe did not run through it, but was just a shallow surface feature. Whatever the explanation, I am both disappointed...and curious. What is this thing? Rarely have I had a stone be so completely altered by relatively slight polishing. Still handsome, but nothing like it was...