| 1. | Tetragonal, trigonal and Isometric minerals cannot exhibit pleochroism.
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| 2. | Brookite exhibits very weak pleochroism, yellowish, reddish and orange to brown.
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| 3. | Sampleite is anisotropic and has visible pleochroism and birefringence.
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| 4. | Marthozite shows pleochroism from yellowish brown to greenish yellow.
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| 5. | Pleochroism is moderate, from pink-orange or purplish pink to pinkish purple.
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| 6. | The mineral displays strong pleochroism and weak anisotropy.
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| 7. | They may exhibit pleochroism or double refraction.
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| 8. | Tourmaline is notable for exhibiting strong pleochroism.
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| 9. | The mineral also exhibits white to blue-tinted-white pleochroism under reflected light.
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| 10. | In plane polarized light, suessite is a reddish-brown color that shows no pleochroism.
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