Don't forget the organic matter either , NT .

If you want to know the proportions of the sand , silt , OM , and clay in your soil take a quart mason jar and fill it halfway with a sample of soil and then fill to within 1" from the top with water . Put the lid on and shake it until the sample is completely broken down in the water and then set the jar aside until the next day . The ingredients in your soil will stratify by weight showing you their relative proportions in the soil . Measure the height of the whole strata and then the individual layers with a metric rule to determine their percentages .