Those who have traveled through the Texas panhandle know that the region is a flat plain, cut by the passage of water (to create such marvels as Palo Duro Canyon. But north of Amarillo there is an ancient buried mountain range that pushed to the surface and is the source of metamorphic minerals (rubies, etc.) and in Central Texas there are remnant ancient mountains that have igneous granite, quartz, tourmaline, silver, etc. and topaz. While topaz is number 9 on the Moe hardness scale (diamond being 10), it formed in igneous areas, versus diamonds as carbon under pressure in metamorphic areas. Who knows, maybe one day they'll find diamonds in the Texas Panhandle.

Anyway, this riff is offered up as an appreciation of ancient rocks that stick up out of the newer surrounding stuff. It can be very interesting.