Which characteristic describes sagenitic quartz?

Sagenitic quartz is characterized by its transparency and the presence of eye-visible inclusions. These inclusions are typically composed of needle-like or fibrous structures, often made up of minerals such as rutile or tourmaline, giving the stone a distinctive appearance. The ability to see these inclusions with the naked eye not only defines sagenitic quartz but also adds to its beauty and uniqueness, making it a sought-after variety among collectors and gem enthusiasts.

The other characteristics attributed to sagenitic quartz do not apply correctly. For instance, sagenitic quartz is not devoid of inclusions—rather, its defining feature is these noticeable inclusions. While transparency is a trait of this quartz variety, it does not align with the characteristics of opaqueness or uniform coloration. Additionally, sagenitic quartz is not restricted to being found exclusively in sedimentary rocks, as it can occur in various geological formations, making sedimentary origin irrelevant to its classification.