Anglesite is a lead sulfate mineral with the chemical formula PbSO4. It is a secondary lead mineral that always forms through the alteration of lead sulfides, primarily Galena. It occurs as an oxidation product of primary lead sulfide ore, Galena. Anglesite occurs as prismatic orthorhombic crysta.....

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### Andyrobertsite

Andyrobertsite is a rare, complex arsenate mineral with a blue color. It is found in the Tsumeb mine in Namibia and named after Andrew C. Roberts (b. 1950), a mineralogist with the Geological Survey of Canada. A Ca-rich analog (with Ca instead of Cd) is called calcioandyrobertsite and has a more .....

### Andradite

Andradite is a species of the garnet group. It is a nesosilicate, with formula Ca3Fe2Si3O12. It is a member of the Garnet group, and although not as well-known as other Garnets such as Almandine or Pyrope, it is still fairly abundant and can produce fine Garnet gemstones. Andradite includes three.....

### Andesine

Andesine is a silicate mineral, a member of the plagioclase feldspar solid solution series. Its chemical formula is (Ca, Na)(Al, Si)4O8, where Ca/(Ca + Na) (% anorthite) is between 30%-50%. It is a red feldspar gemstone, sometimes with greenish hints and a slight labradorescent effect. The plagio.....

### Condition for Common Root of Quadratic Equations

Condition for Common Root of Quadratic Equations A polynomial of the second degree is generally called a quadratic polynomial. In elementary algebra, the quadratic formula is the solution of the quadratic equation. There are other ways to solve the quadratic equation instead of using the quadrati.....

### Finding Missing Number in a Sequence

Finding Missing Number in a Sequence A Sequence is a set of things (usually numbers) that are in order. To find a missing number, first, find a Rule behind the Sequence. How to find a missing number in a sequence Determine if the order of numbers is ascending (getting larger in value) or descendi.....

### Andersonite: Properties and Occurrence

### Andalusite: Properties and Occurrence

Andalusite is an aluminum nesosilicate mineral with the chemical formula Al2SiO5. It is a polymorph with two other minerals: kyanite and sillimanite. Andalusite is trimorphic with kyanite and sillimanite, being the lower pressure mid temperature polymorph. It is not Radioactive. It is usually onl.....

### Important Reasons for Physical Activity

### Anatase

Anatase is one of the three mineral forms of titanium dioxide (TiO2), the other two being brookite and rutile. At higher temperatures, about 915 degrees Celsius, anatase will automatically revert to the rutile structure. It is always found as small, isolated and sharply developed crystals, and li.....

### Irrational Roots of a Quadratic Equation

A polynomial of the second degree is generally called a quadratic polynomial. In elementary algebra, the quadratic formula is the solution of the quadratic equation. There are other ways to solve the quadratic equation instead of using the quadratic formula, such as factoring, completing the squa.....

### Ancylite

Ancylite is a group of hydrous strontium carbonates minerals containing cerium, lanthanum and minor amounts of other rare-earth elements. The composition is Sr(Ce, La)(CO3)2(OH)·H2O with ancylite-Ce enriched in cerium and ancylite-La in lanthanum. It is uncommon to a rare mineral that can be fou.....