Mustang soared by A1.3c to 3.9c after it announced it had sent a parcel of 6221 carats of rubies and corundum to leading American gemstone cutters and jewellers in California, seeking advice on marketing strategies and the range in potential ruby values.

The rising price was good news for the Australian and US investors who bought into the company's oversubscribed placement of 133.4 million shares at 2.1c last month.

Mustang managing director Christiaan Jordaan said the shipment would help the company place market values on its rubies as well as growing awareness and understanding of the stones.

"As a result, we will be better placed to estimate the revenue we can generate from our rapidly growing production profile," he said.

Prospecting teams at the Montepuez project have been responsible for the recovery of 13,314.76 carats to date, of which 5406 carats were sent to the US.

The remaining rubies in the 6221 carat parcel were recovered from a bulk-sampling program at the deposit, which has recovered 1638.76 carats from a 15,585 cubic metre stockpile of ruby-bearing gravel, with 7290.5cu.m processed so far.

A parcel of five special stones weighing a total of 76.65 carats, including two rare 24 carat high quality rubies, will be cut by specialist gemstone cutter Meg Berry, which Mustang said could help influence the value of the stones.

The company says many of its stones are suitable for cutting without heat treatment, with some field experts citing the Montepuez field as the single largest supplier.

The move comes after the company relocated its processing plant closer to its key Alpha ruby deposit and important water sources late last year, which it said was part of a strategy to ramp up production and generate sales revenue.

Ramping up production at the facility to its targeted rate of 525 tonnes per day was the first order of business for the quarter, Jordaan said, with initial plant relocation results suggesting the company could triple its throughput rates from prior levels.