Hardness of gems

The Mohs scale rates the hardness of materials, and is based on these minerals (from softest to hardest):

Talc Gypsum Calcite Fluorite Apatite Feldspar Quartz Topaz Corundum Diamond

Trumpets give chilling forms after frigid queens twirl crimson dice
Tacos grab complicated foreigners after friendly questions train creepy dietitians
Tall gleeful careless fantastic architects flail quick tiny cyan doilies

Layers of sediment in the Grand Canyon

From the bottom up:

Tapeats, Bright Angel, Muav, Redwall, Supai, Hermit, Coconino, Toroweap, Kaibab

Tall broken mad robots strangle huge chilling toxic killers
Tainted boring malodorous ravens smoke horribly creepy thin kitties