What Minerals Are Softer Than A Fingernail?

What Minerals Are Softer Than A Fingernail? MINERAL NAME LUSTER (appearance) HARDNESS Fluorite Non-metallic (purple, green, yellow) Softer than glass Calcite Non-metallic Softer than glass Halite Non-metallic Softer than glass Gypsum Non-metallic Softer than glass and softer than a fingernail What minerals have no streaks? Streak is a more reliable property than color because streak