Color

While the color of a particular specimen my be obvious, it is never the best major identifying characteristic.

Azure Black Blue Bluish Black Brass Brown Bronze Copper Colourless Gold Gray Grayish Black Green Olive Orange Pink Red Reddish Brown Ruby Silver Steel Turquoise Vermillion Violet White Yellow Brown Unknown

Streak

The streak is the color produced when a mineral is powdered or drawn across a piece of unglazed porcelain. It is often quite different from the apparent color of the mineral, especially if it has a metallic luster.

Azure Black Blue Bluish Black Brass Brown Bronze Copper Colourless Gold Gray Grayish Black Green Olive Orange Pink Red Reddish Brown Ruby Silver Steel Turquoise Vermillion Violet White Yellow Brown Unknown

Luster

Luster is the way light is reflected off the surface of a mineral. The terms used are:

• metallic (like polished metal)
• adamantine (like diamond)
• vitreous (like broken glass)
• resinous (like resin or wax)
• pearly
• silky
• splendant (reflects an image brilliantly)
• shining (reflects an image but not clearly)
• glistening (reflects light but not an image)
• glimmering (reflects from some points on the specimen)

Metallic Adamantine Vitreous Resinous Pearly Silky Splendant Shining Glistening Glimmering Unknown

Transparency

Minerals can be:

• transparent (the outline of objects can be seen clearly through them)
• semi-transparent (objects can be seen through them but are indistinct)
• translucent (light passes through them but objects cannot be seen)
• opaque (no light passes through)

Transparent Semi-transparent Translucent Opaque Unknown

Hardness

Hardness measures how hard a mineral is to scratch or be scratched. It is measures on the Moh Scale:

Moh's Scale value 
between and

Tenacity

Tenacity describes how easily a mineral can be cut. The terms used are:

• sectile (easily cut with a knife)
• brittle (crumbles if hit with a hammer)
• malleable (flattens if hit with a hammer)
• flexible (bends without breaking)

Sectile Brittle Malleable Flexible Unknown

Cleavage

Cleavage is the tendency of a mineral to break along planes of weakness. A good way to recognize cleave is to turn the specimen around in a good source of light and see if there is surface that will reflect the light as if the light were being reflected off a dull mirror.

Perfect Distinct Indistinct Imperfect In Traces None Unknown

Direction(s) of cleavage:

One Two More than Three Three Unknown

Fracture

Some minerals give a distinctive kind of break when hit with a hammer. The terms used to describe these breaks are:

• conchoidal (shell-like)
• subconchoidal (indistinct conchoidal)
• even (leaving a flat surface)
• uneven (leaving a rough, irregular surface)
• earthy (leaving a dull, crumbly surface)
• hackly (with sharp points)

Conchoidal Subconchoidal Even Uneven Earthy Hackly Unknown

Density (Specific Gravity)

The specific gravity of a mineral is its weight compared to water. An indication of specific gravity is how heavy a specimen feels:

Specific Gravity between
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 and  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24