Egg Analyses part iii – Shells

Shells

Clockwise from top left: Venus, Lily, Frida, Poppy, Bessie, Ella, Claire, Neroli

Our final data concern the egg shells themselves. All eight eggs had good, normal-thickness shells. As the photo shows, the pigment that determines the colour of the shell is only laid down in the outer shell.

While we technically have two “colours” of egg (“white” and “brown”), in actual fact the colours range over a fairly broad palette. Colour perception is notoriously subjective, so we used colour swatches from Resene Paints’ Multi-finish range to establish a closest approximation. The results below are from lightest to darkest.

Hen	Colour	Code	Description
Lily	Black White	N93-005-100	longish teardrop shape, pointed, with longitudinal striations (‘rifling marks’)
Neroli	Quarter Spanish White	Y93-015-083	very similar to Frida and Lily in shape, often with small pinkish speckles
Frida	Pearl Lustre	Y94-018-087	long teardrop shape, usually with a ‘suture’ marking at the blunt end
Bessie	Tequila	Y88-049-070	classic egg shape – a rounded teardrop with a slight hint of apricot
Poppy	Manhattan	080-063-064	a slightly elongated version of Bessie’s round teardrop shape, healthy-suntan brown
Ella	Manhattan base Desperado speckles	080-063-064	very rounded teardrop, usually a clear glossy brown with darker speckles
Claire	Whiskey Sour base Chelsea Gem speckles	071-082-061	a longer, thinner egg, usually with a definite point, tends to be a clear coffee brown base with darker speckles
Venus	Kalgoorie Sands	068-060-059	a long oval shape – usually very difficult to work out which end is the ‘point’

Swatches were held up against the eggs under natural light from a north-facing window, in moderate overcast weather conditions, around midday.

The following table expresses the weight of the shells wet, dry (dried in a 100˚C oven for 30 minutes), and expressed as a percentage of the total weight of the egg.

Hen	Wet	Dry	Shell %†
Venus	9 g	6 g	12.5%
Lily	8 g	6 g	12.12%
Frida	9 g	6 g	15%
Poppy	8 g	6 g	12.9%
Neroli	8 g	6 g	13.8%
Claire	7 g	5 g	12%
Ella	8 g	6 g	10.8%
Bessie	7 g	7 g	12.1%