An ice cube-sized hunk of Pyrex fused to a hollow glass tube was rotating over a propane flame in an Inverness Park garage last week. Jason Green waited for it to reach about 2500°F, when he could blow it into a tiny oil lamp—or whatever it might become. “Sometimes you don’t really know what you’re making, because it kind of depends on how the glass moves,” said Mr. Green, a San Geronimo resident and member of a group called the Inverness Park Glassworks, which will sell oil lamps in local shops for the holidays. The glassworks is a collective of three West Marin residents: Mr. Green, who works as a gardener; Kelson Iasiello, a carpenter from Inverness Park; and Tony Smith, also from Inverness Park. The trio started making glass pieces together about a year ago, spearheaded by Mr. Green, who has worked in the medium for about a decade. His work includes making about 125,000 beads for a curtain in a Connecticut casino, as well as what he said were thousands upon thousands of cabinet knobs for other clients. But he liked the idea of a collective, he said, in which no one artist’s name would be attached to a piece. “Glassmaking has traditionally been a team of people making things. And I like to see how other people do it,” he said. Mr. Lasiello only started blowing glass at the invitation of Mr. Green, and he said he’s enjoying learning a new skill. “It’s fun. It’s a challenge, which is a lot of what I enjoy about it,” he said. Glassblowing can be a bit repetitive; it’s not unusual to make dozens of the same object, with maybe two-thirds good enough to sell. But Mr. Green doesn’t tire of making scores of the same thing—he likes trying to “beat the clock” and make as many as he can. But he and Mr. Lasiello said one should be careful not to gaze into the propane flame for too long. “After a while, you’ll see what they call floaters: dots of light in the evening,” Mr. Lasiello said. For now, look for Inverness Park Glassworks pieces at Garageland, in Forest Knolls.