September Birthstone: Sapphire

September's stone and the color of the sky

Sapphire is September's birthstone, and it is the same mineral as ruby with the color removed: corundum, second in hardness only to diamond, blue in every shade from pale cornflower to a near-black navy that only shows its color in direct light. The tradition's preferred tone has changed with the centuries — Victorian buyers wanted the darkest possible stone, modern ones tend to want the brightest — and the same stone was described in completely different words by each generation.

Lapis lazuli is the month's alternative, and it is not a mineral but a rock: a mixture that has been ground into pigment for longer than it has been worn as jewelry. The ultramarine in medieval manuscripts is lapis, which makes it the only birthstone whose primary historical use was painting.

September's recorded qualities are wisdom, clarity, loyalty and calm. All four are claims about the mind rather than about fortune, which puts this month in a small group with February and June.

What sapphire has been kept for

The stone's oldest association is with truth and with the keeping of promises — the two were not separated in the older sources, and both were tied to the blue that does not change when the light does. Sapphire was worn by people who had to give testimony, given to people who were traveling, and set into rings that were meant to be worn for decades.

Loyalty is the quality with the longest record and the most specific use. A sapphire was traditionally the stone of a friendship rather than of a romance, which is a distinction the modern list has quietly lost.

Clarity and wisdom are the two that the Eastern reading emphasizes as well, where blue is the color of the Water phase in some systems and of the deep and the distant in most. The stone appears in this site's animal records more than any other blue mineral, which is a small sign of how widely the association travelled.

None of these claims concern outcomes. Sapphire is presented as a companion for long commitments and clear thinking, not as a source of either.

September's signs and the shared stone

Virgo takes the first three weeks and its recorded stone is sapphire, matching the month exactly. The Virgo page holds that portrait: mutable earth, ruled by Mercury, analytical, meticulous, easier on other people than on itself.

Libra begins around the twenty-third and its stone is opal, the shimmering stone of October. The Libra page carries the record: cardinal air, ruled by Venus, diplomatic, aesthetic, instinctively weighing a room.

So September is one of the months where the calendar and the wheel agree for the earlier sign and separate for the later one. A birthday before the equinox has a single blue answer; a birthday after it has a blue for the date and a shifting iridescent one for the sun. The site keeps a longer write-up of this particular stone on its own page — the sapphire essay covers the same ground at more length, including why the stone survived the twentieth century better than most of its neighbors.

Living with September's stones

Sapphire is the most forgiving stone on the calendar: hard enough for daily wear, unaffected by sunlight, resistant to almost every chemical a household contains, and easy to clean with warm water and a soft brush. Untreated stones in unusual colors — pink, yellow, green — are the same mineral with trace elements in place of iron and titanium, and they carry the same durability.

Lapis is the opposite: a three-to-five on the hardness scale, porous, and prone to damage from water, soap and heat. It should be kept away from cleaning entirely and worn on a surface that does not rub against anything, which is a strange prescription for a stone that people once ground into dust.

The month's neighbors on the list are August with peridot and October with opal — green and iridescent on either side of the year's most solid blue.