Crystals have long been valued for their beauty and energy. Some people even believe that certain gemstones and crystals contain healing properties.

Minerals form when a solution cools to a point that its ingredients begin to form crystals. Different minerals crystallize at different temperatures; when conditions within a crystal change, their colors often change as a result of this. Chrysoberyl may show asterism (star-shaped light reflection) due to inclusions of needlelike rutile which cause light reflection off needlelike inclusions of rutile.

Formation of Crystals

All minerals contain crystal structures-an orderly and repetitive arrangement of atoms known as lattices-that gives each mineral its distinct appearance. There are various processes by which minerals form: igneous minerals form when magma cools; aqueous minerals develop in water sources such as wells or rivers; while metamorphic minerals grow during rock formation.

Minerals take shape according to how they grow, with shapes determined by symmetry and their growth habits. A crystal’s symmetry refers to its arrangement of faces; for instance, six cube faces or eight octahedron faces could all fall within its pattern of faces.

Crystals produce growth rings similar to tree rings that provide insight into their environment of formation. High pressures and temperatures may alter rock chemistry, causing “pseudomorphs” (for example crocidolite could become quartz and azurite could become malachite).

Formation of Gems

Each gem is truly one-of-a-kind as they form under distinct environmental factors – temperature, pressure, chemistry and how much room the crystal has for growth all play an influential role in shaping its color, size and shape.

Gemstones form deep within Earth’s crust or even deeper in its mantle. From magma or hot water laden with minerals, gemstones can form and eventually take form as gemstones.

Some gems also form closer to the surface, like opal and amethyst. These gemstones form when silica-rich water falls onto volcanic rocks in volcanic vents, creating layers of crystals in gas bubbles within volcanic rocks – this gives these gems their distinct water-clear clarity and shapes. Chemistry in their surroundings also contributes to their colors – for instance chromium makes beryl green while manganese turns it pink as in morganite or purple in amethyst.

Mantle Crystallization

The mantle lies between Earth’s crust and core, providing an extremely hot and dense environment in which molten rock creates ideal conditions for gemstone formation – but must first reach the surface through volcanic eruptions or geological processes before emerging as gemstones.

Geologists know that peridots form on rocks in the mantle. Through erosion and mountain building processes, those rocks come closer to the surface where they can be harvested for gem mining or extraction.

Igneous gemstones are fascinating products of Earth’s natural processes. Mineral-rich water seeps into cracks and cavities and starts crystallizing, producing gemstones with various mineral compositions within one stone; this “on-and-off pattern of growth,” called twinning, produces dramatic color zoning effects similar to what can be found with opal.

Volcanic Eruptions

Volcanic eruptions have a powerful impact on natural crystals and gemstones. From fountains of glowing-red lava to terrifying explosions that send clouds of scorching hot ash cascading down volcanoes, volcanic activity has an immense effect on gem formation. High temperatures and pressures within volcanic environments facilitate gem growth by encouraging atoms to arrange in the patterns characteristic of crystals.

Magma that emerges from deeper levels of the Earth often contains upper mantle minerals like olivine and pyroxene from upper mantle plumes that have been released as xenoliths from deep crust layers; these serve as sources for peridot, which is found worldwide volcanic deposits.

Opal gemstones require lower temperatures and pressures than most gems to form. Opals typically form closer to the surface when mineral-rich water seeps into cracks in rocks before cooling and solidifying into gemstones.

Mountain Erosion

Crystals have long been prized gems. Quartz (SiO2) and its color variants – such as amethyst, citrine, rose quartz and smoky quartz – can be found throughout silica-rich igneous rocks; often occurring as cavities, geodes or fragments/cryptocrystalline aggregates such as chalcedony and agate.

Mining gems has major environmental repercussions, with ecosystem degradation being one of the primary effects. When forests are cleared to make way for gem digging operations, animals living within that ecosystem either have to relocate or perish as part of this process.

Topaz can be found in alpine clefts of Switzerland’s Alps, while tourmaline from Binn Valley stands out for its range of colors. Unfortunately, many gems such as topaz come from mines which may not be as eco-friendly.