Glass and Handwriting

What is the main ingredient in glass and what is its chemical name?

The main ingredient in glass is Silicone Dioxide or SiO2

What is chromatography?

the separation of a mixture by passing it in solution

Word and Letter Spacing

what is the average space between words and letters?

Amorphous

when an item's atoms are arranged randomly

Beginning and Ending Strokes

where do the letters begin and end on a page

Line Features

writing speed, pen pressure, spacing between letters and words and how they are connected

Compare and contrast the entrance and exit holes of glass that has been shot with a bullet. Which side does shattered glass usually land on?

Exit holes are normally larger than entrance holes The glass blows back and lands on the side of the entrance hole

What type of evidence (class or individual) is glass usually considered to be? Why?

General composition of glass is a class characteristic It is either too fragmented or too small to permit a comparison

What does it mean if something is "amorphous" and how does that affect the way glass breaks?

If something is amorphous, it means that the item's atoms are arranged randomly. Because of this, it produces a variety of fracture patterns when broken

Density

Mass per unit volume

What is the "4 R Rule" regarding conchoidal lines?

On Radial cracks, Ridges make Right angles to the Rear

How can analyzing radial fractures help you determine the sequence of multiple bullet holes?

The radial fractures from the second bullet hole always terminates into the first bullet hole and so on, so you can see which bullet hole doesn't terminate into one, which would be your first and then you can see which ones terminate into each other

How can you find the volume of a fragment of glass using a graduated cylinder?

You can measure the glass' mass on a scale then find the volume through water displacement in the graduated cylinder by recording the initial volume of the cylinder without anything in it then place the glass fragment in the cylinder and subtract the original volume from the new volume. That is the volume of the glass fragment that will then be used to divide the mass by.

Obsidian

a natural form of glass created by volcanoes

Unusual Letter Formation

are any letters written with unusual slants and angles? are some letters printed rather than in cursive?

Fluxes

changes formers' melting points Ex: Sodium carbonate and potassium carbonate

Laminated Glass

constructed by bonding two ordinary sheets of glass together with a plastic film also used by automobile manufactures

Leaded Glass

contains lead oxide which makes it dense sparkles as light passes through it used for manufacturing fine glassware and art glass commonly called crystal

Slant

do any of the letters slant left or right

Line Quality

do the letters flow or are they written with very intent strokes?

Pen Lifts

does the author lift his or her pen to stop writing a word and start a new word

Baseline Habits

does the author write on the line or does the writing go above or below the line

Silicone Dioxide

example of a former (makes up the bulk of glass)

Concentric Fracture

form second, encircle the bullet hole start on the same side as the destructive side

Content

grammar, punctuation and word choice

Glass

hard, brittle amorphous material

Connecting Strokes

how are the capital letters connected to the lower case letters

Margins and Format

how big or small are the letters how far are they from the margins

Letter Comparison

how do the letters differ from the norm

Placement of Diacritics

how does the author dot the i's or cross the t's

Shading or Pen Pressure

how much pressure is applied on upward and downward strokes

Formers

makes up the bulk of the glass Ex: Silicone Dioxide in the form of sand, boron trioxide, and phosphorus pentoxide

What type of chromatography did we do?

paper chromatography

Radial Fracture

produced first, form on the side of the glass opposite to where the impact originated looks like spider webs that spread outward from the impact hole always terminate into an existing fracture

Stabilizers

strengthen the glass and make it resistant to water Ex: Calcium carbonate

Tempered Glass

stronger than ordinary glass strengthened by introducing stress through rapid heating and cooling of its surface breaks into fragments or small squares used in the side and rear windows of cars

Soda - Lime Glass

the most basic, common inexpensive glass easiest to make

Overall Format

the size, shape, slant, and strokes of the letters