Stone Art Visions Glossary

Agate - Agate is a variety of chalcedony (a family of microcrystalline quartz). Agate is a very common stone that is often used in jewelry. It is found in a wide range of colors, including black, gray, brown, reddish, green, pink, blue, and yellow. Agate can be flecked with color and is often banded, exhibiting layers of quartz. Agate is porous and takes dye easily; it is frequently dyed to enhance the coloration and the banding. White agate was used often in Victorian jewelry, mostly as a background. Moss agate has green, red or black dendritic inclusions. Onyx is agate whose bands are parallel. Eye agate has banding arranged in concentric circles. Agate has a hardness of 6.5 to 7 and a specific gravity of 2.6.

Amethyst - Amethyst is a form of quartz in shades of purple ranging from light lavender to deep, intense purple with subtle flashes of red. Amethyst is one of the most prized varieties of the Quartz family of gemstone minerals. It has been described since the time of the ancient Greeks. According to ancient legend, you'll never go blind if you wear this beautiful purple birthstone for the month of February.


Ammonite - This photo shows an ammonite and labradorite from Madacascar. Alligaticeras, an extinct fossil cephalopod from the family Perisphinctidae, lived in shallow seas which covered what is now Madagascar during the mid-Jurassic, approximately 180,000,000 years ago. The chamber has been cut and carefully polished to show septa that separate former living chambers, which are now filled with calcite.

Brass - An alloy of copper and zinc.

Fluorite - Fluorite has been used for carvings since the times of the Romans. Natural fluorite is known for its classic cubic crystals and the variety of colors it occurs in. Also known as Fluorspar, this gemstone can be found in England, Germany, Italy, Norway, United States and more. Many of the beautiful carvings available from Stone Art Visions are from rough stocks mined and polished in China.

Fossil - A remnant or trace of an organism of a past geologic age, such as a skeleton or leaf imprint, embedded and preserved in the earth's crust.

Geodes - The term geode is derived from the Greek word Geoides which means "earthlike." A geode is a sphere or oval shaped rock which contains a hollow cavity lined with crystals. Some geodes are completely filled with small compact crystal formations such as agate, jasper or chalcedony and are called nodules. The only difference between a geode and a nodule is that a geode has a hollow cavity, and a nodule is solid. Geodes begin as bubbles in volcanic rock or as animal burrows, balls of mud or tree roots in sedimentary rock. Over time, the outer shell hardens and water containing silica precipitation forms on the inside walls of the hollow cavity within the geode. The silica precipitation can contain many varieties of dissolved minerals, the most common being quartz, but calcite, amethyst and many others are also found. Over a period of millions of years, layers of silica cool, forming crystals of different minerals within the cavity. Different types of silica cool at varying temperatures, thus creating layers of different types of mineral crystals.

Granite - Granite is one of the much sought after natural stones. It is popular all over the world for its quality and vibrant colors. Natural granite stone is typically hardest of the dimensional stones and can effectively withstand the vagaries of nature. Natural granite is bold, luxurious and sophisticated, ideal for commercial and residential applications. Granite is best used for kitchen counters and is also suitable for flooring or paving, wall cladding, all types of counter tops and memorials.

Jade - A gem variety of both Jadeite and Nephrite. Valued for its beauty and appreciated for its many colors.

Marble - A marble is a metamorphic rock formed by alteration of limestone or dolomite, often irregularly colored by impurities and used especially in architecture and sculpture. Marble tiles are suitable for bathrooms, entryways and fireplaces, living and dining areas. Marble floor tiles are also used for both interior and exterior flooring applications. Some of the different colors of marble are white, red, black, mottled and banded, gray, pink, and green.

Malachite - A green mineral with banded light and dark green designs with an unique ornamental quality unlike that of any other stone.


Onyx - Onyx is a semi-precious stone prized as a gemstone because of its delicate translucence and clarity of colors. Onyx is a species of chalcedony (microcrystalline quartz). Onyx, also called Travertine or Flow Stone, is formed by hydro-thermal alteration of limestone. Hot underground water dissolves calcium carbonate in the limestone, and it is precipitated as onyx. The banding results from continuous sequential deposition of the carbonate minerals. Different colors are caused by trace amounts of impurities. This beautiful stone is from the Balochistan Province in western Pakistan. Skilled artisans turn solid stone blocks on lathes to create beautiful bowls, vases and plates. Onyx is soft with a hardness of 3. Use care to protect the polished surface. Acidic food and wine will dull the surface of the stone items. No dishwasher or microwave, please.

Quartz - Quartz is the most common mineral found on the surface of the earth and can be found in an impressive range of varieties and colors.


Spiral Shell - The wine goblets in the gift box are spiral shell. The 2 standing pairs are white onyx and banded onyx. Spiral shell limestone filled with gastropods was formed during the Tertiary period between 15 and 40 million years ago. Limestones are sedimentary rocks that formed at the bottoms of lakes and seas, as silt and organic matter settle to the bottom. As more and more layers build up over time, adding more and more weight, heat and pressure cause reactions to take place that lithify the sediments into solid stone. This limestone is found, turned on lathes and polished by skilled artisans in Pakistan. Use care to protect the polished surface. Acidic food and wine will dull the surface of the stone items. No dishwasher or microwave, please.

Sodalite - Beautiful scarce mineral, named for its sodium content.