This transparent colorless variety of Quartz is still known as rock crystal. Long ago, people believed that rock crystal was a compact form of ice: crystallos actually means “frozen.” The best rock crystal has the clarity and shimmer of crystal clear water. Although colorless Quartz is relatively common, large flawless specimens are not, which is why most crystal balls these days are made of glass, not Quartz.
There are two main varieties of quartz, though they share the same chemical composition, silicon dioxide. Macrocrystalline quartz, includes stones like amethyst, aventurine, rock crystal, blue quartz, citrine, hawk’s eye, prasiolite, quartz cat’s eye, smoky quartz, rose quartz and tiger’s eye. The quartz is mostly transparent to translucent. Cryptocrystalline quartz, with microscopically small crystals, is known as chalcedony, and includes agate, chrysoprase, bloodstone, jasper and carnelian. Crytocrystalline quartz is usually opaque or translucent.
This particular rock crystal quartz specimen has been shaped into the form of an obelisk, which makes it a perfect gift or desk decoration for earth science teachers or for geology enthusiasts.
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