Garnets are generally somewhat susceptible to heat (and to some acids) so it is recommended that garnets be cleaned with soft, non-abrasive, dampened cloths. Garnets may abrade along facet junctions if scraped.
Garnets have been used since antiquity, especially as engraved gemstones, and such gems are highly collectible. In reddish garnets the size and pureness of color is highly desirable. Green garnets are almost always small - gems over 3 carats are considered rare and are therefore collectible. Demantoids often have signature "horsetail" inclusions composed of byssolite and/or chrysotile. Clever cutters will attempt to leave such inclusions in the center of the gem to exhibit a classic, collectible gem.