A 137.7-gram Sikhote-Alin meteorite "individual" displaying characteristic regmaglypts (thumbprints)

The eminent Russian meteoriticist, E. L. Krinov, visited the fall site and recovered numerous specimens, which ended up in the Russian Academy of Sciences. Some of his team’s finds were lying on pedestals of snow, never having actually touched the ground, and displayed a blue/grey fusion crust. Krinov wrote an entire book about Sikhote-Alin, but it has, sadly, never been translated into English.

Scientists, and later, collectors, noted that there are two distinctive types of Sikhote-Alin meteorites: shrapnel and individuals. Shrapnel fragments are the result of in-flight explosions of large masses which produced twisted, angular shards reminiscent of bomb case shrapnel, hence their name. Individuals flew though the air as autonomous entities and ablation in the atmosphere caused them to acquire remarkable and sculptural shapes. Individuals frequently display regmaglypts, which are thumbprint-like indentations caused by surface melting.

One face of the 2,785-gram Sikhote-Alin "Missing Link" displays all the typical qualities of shrapnel

One of the intriguing questions about the Sikhote-Alin fall is where and when did the shrapnel-producing detonations take place. After examining a recent acquisition which we call “The Missing Link,” we are able to put forward a hypothesis. Until now, Sikhote-Alins fell into one of two categories, but a recently discovered shrapnel/individual hybrid demonstrates that there are, in fact, three types of Sikhote-Alin meteorite.

The piece in question weighs 2,785 grams and is roughly pentagonal in shape. One large face and two edges are typical of shrapnel specimens: their surfaces are torn and distressed; one face and one edge, remarkably enough, bear the obvious characteristics of individuals in that they are covered with large, oblong regmaglypts.

The exterior face of "The Missing Link" exhibits large and well-formed regmaglypts

The pioneering American meteoriticist H.H. Nininger noted a correlation between the size of regmaglypts and the size of the individuals upon which they appear: the larger the mass, the larger the thumbprints on its surface. The regmaglypts on our shrapnel/individual hybrid are extremely large: one of them is 32.5 mm in length. This tells us that the original meteoroid—prior to fragmentation—was massive. This fascinating meteorite also suggests that the in-flight fragmentation which formed the Sikhote-Alin shrapnel pieces occurred relatively late, and probably close to the ground. It is also interesting to note that shrapnel specimens are associated with the 100+ craters in the Sikhote-Alin strewnfield. While at first glance this suggests that shrapnel was formed by explosive cratering events, some shrapnel specimens display tiny impact pits, which must have been caused by the in-flight impacts of smaller meteorites.

The regmaglypts on our 2.785-kg specimen took time to form. The original mass needed to heat up and melt during flight, before finally exploding. So, what we are looking at here is a surviving piece of the exterior of one of the largest, or perhaps the largest original masses of Sikhote-Alin. The oversize, well-formed regmaglypts demonstrate that it was once part of a very large individual, while its twisted shrapnel-like areas show that it also fragmented in flight.

Detail of regmaglypts on the 2,785-gram "Missing Link"

Sikhote-Alin is my favorite meteorite, and I have handled literally thousands of specimens over the past decade and a half. “The Missing Link” is the single most intriguing piece out of all of them, and in the words of Aerolite’s operations manager and staff geologist: “Well, that’s just cool!”

Learn more about the Sikhote-Alin witnessed fall >>>

Photographs by Suzanne Morrison © Aerolite Meteorites LLC
All rights reserved. No reproduction without written permission.
The owner strictly enforces intellectual property rights.

Remarkably well defined flowlines on a Millbillillie meteorite

Millbillillies typically exhibit a dazzling color combination: black fusion crust mixed with bright orange Australian desert soil which adhered to the crust, producing a visual contrast of unique and striking beauty.

This 17.5-gram Millbillillie displays abundant flowlines and a glossy, black fusion crust

The Millbillillie fall occurred in October of 1960, and was witnessed by only two men, near the town of Wiluna in Western Australia. It was ten years until the first stone was found. These intriguing space rocks often exhibit distinct orientation, glossy fusion crust, contraction cracks, rollover lips, and some of the most highly defined flowlines of any meteorite.

This full slice of the Millbillillie eucrite shows its unusual internal structure which, unlike most meteorites, is devoid of iron

Some meteoriticists believe that the HED group meteorites may have come to us from the large asteroid Vesta which was discovered in 1807 by the German astronomer Olbers. With a diameter of more than 500 km, Vesta is the second-largest body in the Asteroid Belt. If these alluring space rocks do, in fact, count Vesta as their parent body then they are among a tiny number of meteorites—along with lunars and martians—with a specific known point of origin.

See other examples of the Millbillillie meteorite >>>

Photographs by Suzanne Morrison © Aerolite Meteorites LLC
All rights reserved. No reproduction without written permission.
The owner strictly enforces intellectual property rights.

Around 1 am on the morning of February 8, the family was awakened by a bright light and shaking. The shutters flew open and the night was illuminated by a tremendous fireball, followed by a loud boom. “It was almost like high noon,” Vicki recalls. Vicki remembers her father getting a radio or news report, of some kind, about where the impact site might be. The family piled in their van and drove 60 or 70 miles, which took several hours.

The Allison family in Mexico, around the time of the Allende fireball

Shortly after daybreak they arrived at an open field, where several locals were wandering around in a daze. The meteor had exploded in the air and showered the area with multiple pieces, but nobody yet knew exactly what had happened. Mr. Allison saw an odd looking rock on the ground, and “knew it was something unusual,” Vicki remembers. He carried it to the van, and put it in the back.

The family later returned to the United States, and the “unusual rock” was given to Vicki. It was used as a doorstop for many years, until Vicki’s brother saw a show about meteorites on the Discovery Channel and decided to have the Mexican rock examined.

The Allison Allende carbonaceous chondrite (CV3.2) fell to earth on February 8, 1969 in Chihuahua, Mexico. Specimen weight is 4,467 grams, making it one of the largest of its type offered for private sale. As the stone was picked up immediately after the fall it still exhibits a fresh fusion crust.

The owners contacted Aerolite Meteorites who offered to work with the family and find a good home for this important meteorite. The Allison Allende was a featured exhibit during the 2008 Tucson gem and mineral shows. It was recently purchased by a private collector in the United States and can look forward to a brighter furture than its previous life as a doorstop.