page_title: Grandidierite
hierarchical_section_title: Grandidierite
caption_attribution_description: English: World's Largest Cut Grandidierite 429.87 Carats Grandidierite Owned By a Filipino collector Benedicto G. Membrere V
context_page_description: Grandidierite is a rare mineral that was first discovered in 1902 in southern Madagascar. The mineral was named in honor of French explorer Alfred Grandidier who studied the natural history of Madagascar.
  Grandidierites appear bluer in color the more iron they contain. A recently discovered gemstone, blue ominelite is the Fe-analogue to grandidierite.
  Grandidierites display strong trichroic pleochroism. That means they can show three different colors depending on the viewing angle: dark blue-green, colorless, or dark green.
  While trichroism can usually help distinguish grandidierites from other gems, lazulites can occur with blue-green colors and show colorless/blue/dark blue pleochroism. Nevertheless, lazulites have somewhat higher refractive indices and specific gravity. Grandidierites also have greater hardness.
context_section_description: Grandidierite is a rare mineral that was first discovered in 1902 in southern Madagascar. The mineral was named in honor of French explorer Alfred Grandidier (1836–1912) who studied the natural history of Madagascar.
  Grandidierites appear bluer in color the more iron (Fe) they contain. A recently discovered gemstone, blue ominelite is the Fe-analogue (Fe, Mg) to grandidierite (Mg, Fe).
  Grandidierites display strong trichroic pleochroism. That means they can show three different colors depending on the viewing angle: dark blue-green, colorless (sometimes a very light yellow), or dark green.
  While trichroism can usually help distinguish grandidierites from other gems, lazulites can occur with blue-green colors and show colorless/blue/dark blue pleochroism. Nevertheless, lazulites have somewhat higher refractive indices and specific gravity. Grandidierites also have greater hardness.
caption: The world's largest known cut grandidierite, a 429.87 carat stone owned by a Filipino collector Benedicto G. Membrere V. GIL Report certificate number STN201811139168
exif: {"Image ImageWidth": "5312", "Image ImageLength": "2988", "Image Make": "samsung", "Image Model": "SM-G900F", "Image Orientation": "Horizontal (normal)", "Image XResolution": "72", "Image YResolution": "72", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "G900FDXS1BQB1", "Image DateTime": "2019:06:29 06:54:40", "Image YCbCrPositioning": "Centered", "Image ExifOffset": "238", "GPS GPSVersionID": "[2, 2, 0, 0]", "Image GPSInfo": "3152", "Thumbnail ImageWidth": "512", "Thumbnail ImageLength": "288", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail Orientation": "Horizontal (normal)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "3300", "Thumbnail JPEGInterchangeFormatLength": "7770", "EXIF ExposureTime": "1/30", "EXIF FNumber": "11/5", "EXIF ExposureProgram": "Program Normal", "EXIF ISOSpeedRatings": "80", "EXIF ExifVersion": "0220", "EXIF DateTimeOriginal": "2019:06:29 06:54:40", "EXIF DateTimeDigitized": "2019:06:29 06:54:40", "EXIF ComponentsConfiguration": "YCbCr", "EXIF ShutterSpeedValue": "49/10", "EXIF ApertureValue": "227/100", "EXIF BrightnessValue": "61/25", "EXIF ExposureBiasValue": "0", "EXIF MaxApertureValue": "57/25", "EXIF MeteringMode": "CenterWeightedAverage", "EXIF LightSource": "Unknown", "EXIF Flash": "Flash did not fire", "EXIF FocalLength": "24/5", "EXIF SubSecTime": "780", "EXIF SubSecTimeOriginal": "780", "EXIF SubSecTimeDigitized": "780", "EXIF FlashPixVersion": "0100", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "5312", "EXIF ExifImageLength": "2988", "Interoperability InteroperabilityIndex": "R98", "Interoperability InteroperabilityVersion": "[48, 49, 48, 48]", "EXIF InteroperabilityOffset": "3122", "EXIF SensingMethod": "One-chip color area", "EXIF SceneType": "Directly Photographed", "EXIF ExposureMode": "Auto Exposure", "EXIF WhiteBalance": "Auto", "EXIF FocalLengthIn35mmFilm": "31", "EXIF SceneCaptureType": "Standard", "EXIF ImageUniqueID": "F16QLHF01VB"}