5.3" Polished, Free-Standing Blue Lace Agate - Malawi

This is a gorgeous polished section of blue lace agate collected from Sanje, Malawi. The blue coloration of this specimen is truly wonderful and vibrant. These chalcedony veins are formed by hydrothermal deposition within large cracks in rock.

Small calcite crystals can be found within the crystal lined cavity at the top of this free-standing specimen. The base of this specimen has been cut flat, allowing for presentation without the need for a display stand.

About Agate

Agate is a variety of microcrystalline quartz (chalcedony) that displays translucence and, in some cases, banding. Agate primarily forms when silica-rich fluids fill pockets within rocks and/or fossils, depositing the silica along the walls of the rock. This process can result in banding patterns, as the compositions and impurities of these depositing fluids change over time. These banding patterns can either form as flat layers, creating linear patterns known as waterline agate, or as rounded layers, forming more common ring-like patterns. These patterns depend on the surfaces available for deposition.

About Quartz

Quartz is the name given to silicon dioxide (SiO2) and is the second most abundant mineral in the Earth's crust. Quartz crystals generally grow in silica-rich environments--usually igneous rocks or hydrothermal environments like geothermal waters--at temperatures between 100°C and 450°C, and usually under very high pressure. In either case, crystals will precipitate as temperatures cool, just as ice gradually forms when water freezes. Quartz veins are formed when open fissures are filled with hot water during the closing stages of mountain formation: these veins can be hundreds of millions of years old.

About Calcite Crystals

Calcite crystals are a form of calcium carbonate (CaCO₃) known for their diverse shapes, transparency, and vibrant range of colors. They typically form in rhombohedral, scalenohedral, or prismatic shapes, often with well-defined, sharp edges and glossy surfaces. Calcite crystals are often translucent or transparent, sometimes displaying a double refraction effect where objects viewed through the crystal appear doubled. They can appear in various colors—white, clear, yellow, pink, blue, green, and orange—depending on impurities or trace minerals.

A notable characteristic of calcite is its reaction with weak acids like vinegar, which causes it to effervesce, or fizz, as it releases carbon dioxide. This property makes calcite crystals a key tool in geological identification and studies. Calcite forms in many environments, from sedimentary rocks like limestone and marble to hydrothermal veins.
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DETAILS
SPECIES
Chalcedony var. Quartz & Calcite
LOCATION
Sanje, Malawi
SIZE
5.3 x 4.5"
CATEGORY
SUB CATEGORY
ITEM
#128403