Many people with Ehlers-Danlos syndrome have soft, velvety skin that is highly stretchy (elastic) and fragile. Affected individuals tend to bruise easily, and some types of the condition also cause abnormal scarring.
Quartzite is a metamorphic rock that is formed from the sedimentary rock sandstone. Slate is a metamorphic rock that is formed from the sedimentary rock mudstone. Granulite is a metamorphic rock that is formed from the igneous rock basalt.
Metamorphic rocks are almost always harder than sedimentary rocks. They are generally as hard and sometimes harder than igneous rocks. They form the roots of many mountain chains and are exposed to the surface after the softer outer layers of rocks are eroded away.