Murano glass is a famous product of the Venetian island of Murano. Located off the shore of Venice in Italy, Murano has been a commercial port as far back as the 7th century. By the 10th century, the city had become well-known for its glassmakers, who created unique Murano glass.

The process of making Murano glass is rather complex. Most Murano glass art is made using the lampworking technique. As the glass passes from a liquid to a solid state, there is an interval wherein the glass is soft before it hardens completely. This is when the material can be shaped.

The technique known as Millefiori begins with the layering of colored liquid glass, which is then stretched into long rods called canes. Two glassmakers each pull the glass as they walk in opposite directions. After cooling, the glass rod is sliced so that the pattern shows through each slice. Each slice of the millefiori Murano glass is called a murrine.

When cold, these canes are then sliced in cross-section, which reveals the layered pattern. Each layer of molten color is molded into a star, then cooled and layered again. When sliced, this type of murrine has the appearance of many flowers, thus mille (thousand) fiori (flowers).

Galium aparine is an annual plant native to North America and Eurasia. It has several common names, including Bedstraw, Cleavers, Clivers, Goosegrass, Stickywilly, Stickyweed, Catchweed, Robin-run-the-hedge and Coachweed. The long stems of this climbing plant sprawl over the ground and other plants, reaching heights of 2-5 feet.

Both leaves and stem have fine hairs tipped with tiny hooks, making them cling to clothes and fur much like velcro. As they grow quite rampantly and thickly, they end up shading out any small plants that they overrun. The seeds are similar in size to cereal grains, and are a common contaminant in cereals since they are difficult to filter out. The presence of some seed in cereals is not considered a serious problem as they are not toxic.

When dried and roasted, the fruits of this plant can be used to make a coffee-like drink. The plant can also be made into a tea. Galium aparine was traditionally used to treat skin diseases. Herbalists use it to lower blood pressure and body temperature.

The whole plant is considered rich in vitamin C. Its roots produce a red dye, and the tea has been used as an anti-perspirant by the Chinese, and as a relief for head colds, restlessness, and sunburns. As a pulp, it has been used to relieve poisonous bites.

Bedstraw was widely used as a stuffing for mattresses during early medieval times from the 5th century through the 10th century. The densely paniculated flowers make for soft bedding.

The garnet group includes a group of minerals that have been used since the Bronze Age as gemstones and abrasives. It is a key mineral in interpreting the genesis of many igneous and metamorphic rocks via geothermobarometry. Diffusion of elements is relatively slow in garnet compared to rates in many other minerals, and garnets are also relatively resistant to alteration. Hence, individual garnets commonly preserve compositional zonations that are used to interpret the temperature-time histories of the rocks in which they grew. Garnet grains that lack compositional zonation commonly are interpreted as having been homogenized by diffusion, and the inferred homogenization also has implications for the history of the host rock.

Garnet sand is a good abrasive, and a common replacement for silica sand in sand blasting. Mixed with very high pressure water, garnet is used to cut steel and other materials in water jets. Garnet sand is also used for water filtration media. There are different kinds of abrasive garnets which can be divided based on their origin. The largest source of abrasive garnet today is garnet rich beach sand which is quite abundant on Indian and Australian coasts.

Rock garnet is perhaps the garnet type used for the longest period of time. This type of garnet is produced in America, China and western India. These crystals are crushed in mills and then purified by wind blowing, magnetic separation, sieving and if required, washing. Being freshly crushed, this garnet has the sharpest edges and therefore performs far better than other kinds of garnet. Both the river and the beach garnet suffer from the tumbling effect of hundreds of thousands of years which rounds off the edges.

Garnet has been mined in western Rajasthan for the past 200 years, but mainly for the gemstone grade stones. Abrasive garnet was mainly mined as a secondary product while mining for gem garnets and was used as lapping and polishing media for the glass industries.

A volcano is an opening, or rupture, in a planet’s surface or crust, which allows hot, molten rock, ash, and gases to escape from below the surface. Volcanic activity involving the extrusion of rock tends to form mountains or features like mountains over a period of time. The Ancient Romans called volcanoes Vulcano, after Vulcan, their fire god.

Volcanoes are generally found where tectonic plates are diverging or converging. A mid-oceanic ridge, for example the Mid-Atlantic Ridge, has examples of volcanoes caused by divergent tectonic plates pulling apart. The Pacific Ring of Fire has examples of volcanoes caused by convergent tectonic plates coming together. By contrast, volcanoes are usually not created where two tectonic plates slide past one another. Volcanoes can also form where there is stretching and thinning of the Earth’s crust, such as in the African Rift Valley, the Rio Grande Rift in North America and the European Rhine Graben with its Eifel volcanoes.

Volcanoes can be caused by mantle plumes. These so-called hotspots, for example at Hawaii, can occur far from plate boundaries. Hotspot volcanoes are also found elsewhere in the solar system, especially on rocky planets and moons.

The most common perception of a volcano is of a conical mountain, spewing lava and poisonous gases from a crater at its summit. This describes just one of many types of volcano, and the features of volcanoes are much more complicated. The structure and behavior of volcanoes depends on a number of factors. Some volcanoes have rugged peaks formed by lava domes rather than a summit crater, whereas others present landscape features such as massive plateaus. Vents that issue volcanic lava and gases can be located anywhere on a landform.

Other types of volcano include cryovolcanoes or ice volcanoes, particularly on some moons of Jupiter, Saturn and Neptune. Mud volcanoes are formations often not associated with known magmatic activity. Active mud volcanoes tend to involve temperatures much lower than those of igneous volcanoes, except when a mud volcano is actually a vent of an igneous volcano.

Many ancient accounts ascribe volcanic eruptions to supernatural causes, such as the actions of gods or demigods. To the ancient Greeks, volcanoes’ capricious power could only be explained as acts of the gods, while the 16th German astronomer Johannes Kepler believed they were ducts for the Earth’s tears.

Various explanations were proposed for volcano behavior before the modern understanding of the Earth’s mantle structure as a semisolid material was developed. For decades after awareness that compression and radioactive materials may be heat sources, their contributions were specifically discounted. Volcanic action was often attributed to chemical reactions and a thin layer of molten rock near the surface.

Frost is the solid deposition of water vapor from saturated air. It is formed when solid surfaces are cooled to below the dew point of the adjacent air. Frost crystal sizes differ depending on the time and water vapor available. Frost is also usually translucent in appearance.

Window frost, also called fern frost, forms when a glass pane is exposed to very cold air on the outside and moderately moist air on the inside. If the pane is not a good insulator, such as a single pane window, water vapour condenses on the glass forming patterns. The glass surface influences the shape of crystals, so imperfections, scratches or dust can modify the way ice nucleates.

Frost formation is a complex process, and conditions have to be right for it to occur. It forms on surfaces directly from the vapor state without condensing as dew. If dew forms, frost formation is unlikely, even if the temperature drops below freezing.

Frost is more likely to form on surfaces above ground first, such as house roofs, or automobiles, because the air immediately above the ground is usually a few degrees warmer than air a few feet higher. There is some heat transfer from the ground to the air a few centimeters above it. If there is wind, frost will not form. If the skies are cloudy frost will not form, as the clouds reflect the radiated heat from the ground which helps in keeping the lower layers mixed.

The ideal condition for frost formation is a night with clear skies, light winds, and a temperature forecast to be near or a little below freezing. Temperature and water vapor humidity determine the crystalline forms. Ice crystals are responsible for the artistic displays of window frost. The principal axis of a single crystal of ice is perpendicular to the axis of hexagonal symmetry, and as these crystals are formed the patterns of window frost develop.