Physical Properties:
* Hardness: Measured using the Mohs Hardness Scale, which assigns a number from 1 (talc) to 10 (diamond) based on a mineral's resistance to scratching.
* Specific Gravity: Represents the ratio of a mineral's density to the density of water. This is a dimensionless number.
* Cleavage: While not directly numerical, cleavage can be described using numbers to represent the number of cleavage planes and their angles.
* Fracture: While not directly numerical, fracture can be described qualitatively (e.g., conchoidal, uneven, splintery) or quantitatively (e.g., measuring angles of conchoidal fractures).
* Density: Expressed in grams per cubic centimeter (g/cm³).
* Melting Point: Measured in degrees Celsius (°C) or Fahrenheit (°F).
* Refractive Index: A measure of how much light bends when it passes through a mineral. It's a dimensionless number.
Chemical Properties:
* Chemical Composition: Often expressed using chemical formulas (e.g., NaCl for halite), which specify the elements present and their ratios.
* Specific Heat Capacity: The amount of heat required to raise the temperature of one gram of a substance by one degree Celsius. Expressed in Joules per gram per degree Celsius (J/g°C).
* Thermal Conductivity: The ability of a material to conduct heat. Measured in Watts per meter per degree Celsius (W/m°C).
Optical Properties:
* Color: While color is often subjective, it can be quantified using specific color scales or by measuring the wavelength of light reflected by the mineral.
* Luster: Can be quantified using a gloss meter, measuring the amount of light reflected by the mineral surface.
* Birefringence: The difference in refractive index between two directions of light passing through a crystal. Expressed as a number representing the difference.
Note: Some mineral properties are not easily expressed numerically, such as:
* Streak: The color of a mineral's powder.
* Crystal Habit: The shape and form of a mineral's crystal.
* Magnetism: While minerals can be magnetic or non-magnetic, the strength of magnetism isn't always easily quantifiable.
It's important to remember that these properties are often used in combination to identify minerals.
