MINERALS. CRYSTALS. GEMSTONES. FIND OUT MORE. Earthâs crust is made of rock, and rock is made of natural substances called MINERALS. There are three main types of rockâsedimentary, igneous, and metamorphic rock. Each type is produced in different ways.The oldest rocks on Earth were formed about 3.8 billion years ago.INERALS. CRYSTALS. GEMSTONES. FIND OUT MORE. Earthâs crust is made of rock, and rock is made of natural substances called MINERALS. There are three main types of rockâsedimentary, igneous, and metamorphic rock. Each type is produced in different ways.
Twisted Sisters: The Texas Hill Countryâs Most Famous Trio. This route connects the Twisted SistersâHill Country Ranch Roads 335, 336 and 337ânorthwest of San Antonio, Texas. Three Hill Country Ranch Roads, 335, 336 and 337, are known throughout Texas as the Twisted Sisters, and riders come from near and far to enjoy them. For me it is near, just a short ride from my home to the first Sister.
THE RACE This is a 17.8-mile trail race conducted over the historic Shut-In Ridge Trail that begins at Bent Creek near Asheville, NC and climbs over 3,000 feet along the ridgeline of the Blue Ridge Parkway to the Mt. Pisgah parking lot.