Our January 2 nd meeting will feature our Go-To Guy David Bellamy
Knox United Church 2567 Midland Ave, north east corner at Sheppard Ave
Quartz -A Quality Mineral in Quantity
At 12% of the Earth’s crust , quartz is the single most abundant mineral.
Quartz exists in a variety of forms such as crystalline and crypto-crystalline. The crystalline varieties include rock crystal (which is pure quartz) and varieties with color- imparting impurities, such as amethyst ,citrine and rose quartz. The crypto-crystalline varieties are made up of of microscopic crystals that are jam-packed together to form tough, solid masses. These are chalcedonies ,agates and jaspers. All forms of quartz have a hardness of 7 on the Mohs scale and they take a good polish, making them great for lapidary work. Quartz has the minimum hardness required for rings. There aren’t many common materials that are harder than quartz. Thus there isn’t much in the environment that could scratch quartz. Let’s face facts! Our hands are always banging into things. A word of caution though; hardness DOES not equal toughness and a diamond can be broken, so don’t bang your hands into things with force. Anything softer than quartz or with serious cleavage properties should not be worn in a ring. They can be used in earrings and pendants, however.
Most sand is largely quartz and as sand, one of quartz’s biggest uses is in construction. Another big use of quartz is in making glass When melted the atoms that make up quartz are not arranged in any organized fashion. While is this molten state ,various other materials are added to impart desirable properties to glass such as colour ,durability ,thermal expansion, etc. Once the composition of the molten glass is just right, it is cooled fairly rapidly so that the atoms in solid glass are not organized in any way. This is a hallmark of glass.
Quartz also has piezoelectric properties that make it indispensable to our 21st century way of life. To learn why and to learn of the many varieties of quartz, come to the next meeting on January 2, 2019