hardness of rocks chart

The value of N is either 100 or 130 depending on the Rockwell hardness scale used. Similarly, the value of s is either 0.001 mm or 0.002 mm. d is the penetration depth measured from zero points (in mm). Rockwell Hardness Scale

Crystalline, medium hardness (H = 3-3.5), white to gray. Forms te masses. Alternating layers of Earthy white gypsum and gray calcite. Soft H=2 to 3 Fines with HCI. Hard (11=7), conchoidal fracture, variable color (gray to brown). Petrified wood variety displays cellular structure. Fine to coarsely crystalline, yellow to white, lacks fossils but

The hardness of any mineral is defined by its Mohs scale number: harder the mineral, higher its Mohs number. The Mohs scale was devised by a German geologist and mineralogist Friedrich Mohs in 1812. It works by analyzing the ability of a material to scratch the other (softer) material.

The Mohs scale of mineral hardness is a qualitative ordinal scale, from 1 to 10, characterizing scratch resistance of various minerals through the ability 

JPG from PDF file | Geology, Minerals, Rocks and minerals 

The formation of each type of rock is briefly explained, accompanied by color photos of specific rocks (e.g. granite, marble, limestone) that provide examples of each rock type. Photos of 16 rocks and 5 minerals are included on this 17" x 22" chart. Reproducible activities on the back include a rock hardness test, crossword puzzle, and more. ~ Lisa

The Mohs scale of mineral hardness characterizes the scratch resistance of various minerals through the ability of a harder material to scratch a softer 

This is why many gems and stones have a range of hardness, it depends on the specimen. On the chart below minerals with a higher number can scratch all minerals 

Andesite is the name of a family of fine-grained, extrusive igneous rocks that are usually light to dark gray in color. They have a mineral composition that is intermediate between granite and basalt. Andesite is a rock typically found in volcanoes above convergent plate boundaries between continental and oceanic plates.

The Mohs scale of mineral hardness is a qualitative ordinal scale that characterizes the scratch resistance of different minerals through 

Mineral Identification Chart - LECTURE NONMETALLIC MINERALS (listed in decreasing hardness) Review mineral formula to connect to family! H=Hardness; SG = specific gravity Mineral H SG Streak Color (and/or luster) Form Cleavage/Fracture Distinctive properties Garnet X3Y2(SiO4)3 where X and Y are combinations of Ca, Mg, Fe, Al 7 3.5-4.3.