| 21. | The mineral occurs in nepheline syenite pegmatites and granite and aplite greisens.
|
| 22. | It occurs as an alteration product of triphylite in pegmatites.
|
| 23. | It has been found in association with granite pegmatite and in greisen.
|
| 24. | It also occurs in skarn, pegmatite and hydrothermally altered volcanic rocks.
|
| 25. | It is an accessory mineral in some tantalum-rich granite pegmatites.
|
| 26. | The higher temperature pegmatites most likely preceded the hydrothermal deposits.
|
| 27. | In some locations, very coarse-grained pegmatite masses occur with granite.
|
| 28. | Pegmatite may be produced by low degrees of partial melting of the crust.
|
| 29. | It is also found in granite pegmatites and greisens.
|
| 30. | Connected with the borolanite there are other types of nepheline syenite and pegmatite.
|
