| 1. | The resulting intergrowth of the two feldspars is called perthite.
|
| 2. | The intergrowths in perthite have a great variety of shapes.
|
| 3. | Perthite feldspar within a pegmatite often shows gigantic perthitic texture visible to the naked eye.
|
| 4. | Alkali feldspar dominates, commonly represented by orthoclase and the exsolved lamellar albite, form perthite.
|
| 5. | Perthite is typical of many granites.
|
| 6. | This is mostly made from fine grained quartz and Perthite, but is coloured red yellow and brown.
|
| 7. | The largest documented single crystal of perthite was found in Hugo Mine in South Dakota and measured about x x.
|
| 8. | Perthite is an intergrowth of alkali feldspar of intermediate composition : the coarseness of perthitic intergrowths is related to cooling rate.
|
| 9. | In the acid rocks the common feldspars are orthoclase, perthite, microcline, and oligoclase all having much silica and alkalis.
|
| 10. | The alkaline feldspar is not potassic, but generally sodic-potassic, which is characterized by interlocking anorthoclase, called perthite.
|
