Chemical analysis of the feldspar was performed using laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS), and the results were consistent with potassium feldspar. This deposit was first reported by George Frederick Kunz ( Gems and Precious Stones of North America, The Scientific Publishing Co., New York, 1890, p. This new material is reported to be from the Statesville area of North Carolina and contains brown and black exsolution platelets of hematite and ilmenite showing thin-film interference colors along the interface with the host feldspar. The authors recently examined samples of potassium feldspar from a relatively obscure source (see above) that displayed a phenomenon remarkably similar to Australian rainbow lattice sunstone. Because of its array of colors and the crosshatch pattern of exsolution platelets, the material’s trade name is “rainbow lattice sunstone.” This unique material showcases exsolution platelets of hematite and ilmenite that display thin-film interference colors along the interface between the exsolution product and the feldspar host. Of these, one of the most remarkable is orthoclase from the Hart’s Range area in Australia. Several varieties of aventurescent feldspar are well known in the gem trade. Photomicrographs by Nathan Renfro fields of view 3.55 mm. Applied Jewelry Professional ™ Online Diplomaīrown and black exsolution platelets of hematite and ilmenite in feldspar (left) show colorful thin-film interference colors in oblique fiber-optic illumination (right).
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |